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DOE/ER-0674

Summaries of FY 1995

Engineering Research

March 1996

U.S. Department of Energy

Office of Energy Research

Office of Basic Energy Sciences

Division of Engineering and Geosciences

Germantown, MD 20874
Foreword

This report documents the BES Engineering Research Program for fiscal year 1995; it

provides a summary for each of the program projects in addition to a brief program

overview. The report is intended to provide staff of Congressional committees, other

executive departments, and other DOE offices with substantive program information so as

to facilitate governmental overview and coordination of Federal .research programs. Of

equal importance, its availability facilitates communication of program information to

interested research engineers and scientists. The organizational chart for the DOE Office

of Energy Research (OER) on the next page delineates the six Divisions within the OER

Office of Basic Energy Sciences (BES). Each BES Division administers basic, mission

oriented research programs in the area indicated by its title. The BES Engineering

Research Program is one such program; it is administered by the Engineering and

Geosciences Division of BES. Dr. Oscar P. Manley is technical manager of the

Engineering Research Program; inquiries concerning the program may be addressed to

him, in writing, by phone at (301) 903-5822 or by fax at (301) 903-0271 (additional

information and updates are accessible on World Wide Web, http://er.doe.gov.

In preparing this report we asked the principal investigators to submit summaries for their

projects that were specifically applicable to fiscal year 1995. The summaries received have

been edited if necessary, but the press for timely publication made it impractical to have

the investigators review and approve the revised summaries prior to publication. For more

information about a given project, it is suggested that the investigators be contacted

directly.
ENGINEERING RESEARCH PROGRAM WITHIN DOE

Secretary of Energy Deputy Secretary

Under Secretary

Assistant Secretaries Office of Energy Research * Federal Energy Regulatory

· Nuclear Energy Commission

· Conservation and Renewable * Economic Regulatory · Fossil Commission · Defense * Energy Information · Environment, Safety & Health Administration · Environmental Restoration * International Affairs, etc.

II

* Program Analysis Basic Enery SciencesManagement * Magnetic Fusion Special Programs * High Energy and Nuclear Physics * Scie c Compng

* Health and Environmental Research * Scientc ec gy Advisor · Science and Technology Advisor * Field Operations

* Material Sciences Division Engineering and * Advanced Energy Projects

* Chemical Sciences Division Geosciences Division * Energy Biosciences

I I

Engineering Research Program
Introduction

The individual project summaries follow the program overview. The summaries are

ordered alphabetically by name of institution and so the table of contents lists all the

institutions at which projects were sponsored in fiscal year 1995.

Each project entry begins with an institutional-departmental heading. The names of

investigators are listed immediately below the title. The funding level for fiscal year 1995

appears to the right of title; it is followed by the budget activity number (e.g., 01-A).

These numbers categorize the projects for budgetary purposes and the categories are

described in the budget number index. A separate index of Principal Investigators includes

phone number, fax number and e-mail address, where available. The fiscal year in which

either the project began or was renewed and the anticipated duration in years are indicated

respectively by the first two and last digits of the sequence directly below the budget

activity number (e.g., 94-3). The summary description of the project completes the entry.
Program Review

BES Engineering Research

The BES Engineering Research Program is one of the component research programs which

collectively constitute the DOE Basic Energy Sciences Program. The DOE Basic Energy

Sciences program supports energy related research in the physical and biological sciences,

and in engineering. The chief purpose of the DOE Basic Energy Sciences Program is to

provide the fundamental scientific base on which identification and development of future,

national energy options will depend. The major product of the program becomes part of

the body of data and knowledge upon which the applied energy technologies are founded;

the product is knowledge relevant to energy exploration, production, conversion and use.

The BES Engineering Research Program was started in 1979 to help resolve the numerous

serious engineering issues arising from efforts to meet U.S. energy needs. The program

supports fundamental research on broad, generic topics in energy related engineering topics

not as narrowly scoped as those addressed by the shorter term engineering research projects

sponsored by the various DOE technology programs. Special emphasis is placed on

projects which, if successfully concluded, will benefit more than one energy technology.

During the first year several workshops were sponsored for the purpose of identifying

energy related engineering research needs and initial priorities. Representatives from

industry, academic institutions, national laboratories, and leading members of professional

organizations (Engineering Societies Commission of Energy, American Society of

Mechanical Engineers, Society of Automotive Engineers, and Joint Automation and Control

Committee) participated in the workshops. In addition to the participants in the workshops,

staff representatives from the DOE technology programs and other leading U.S. energy

engineering experts made significant contributions to the setting of program priorities.

There resulted from this process a strong confirmation of the need for a long range,

fundamental engineering research program with two major goals. The broad goals that

were established by this process for the BES Engineering Research Program are:

1) To extend the body of knowledge underlying current engineering practice so as to

create new options for enhancing energy savings and production, for prolonging useful

equipment life, and for reducing costs without degradation of industrial production and

performance quality; and

2) To broaden the technical and conceptual base for solving future engineering problems

in the energy technologies.
In this process, it was further established that to achieve these goals, the BES Engineering

Research Program should address the following topics identified as essential to the progliess

of many energy technologies:

1) Advanced Industrial Technology: improvement of energy conversion and utilization.

opening new technological possibilities, and improvement of energy systems.

2) Fluid Dynamics and Thermal Processes: broadening of understanding of heat transfer

in nonsteady flows, methodology for reducing vibrations and noise in heat exchangers. and

engineering aspects of combustion.

3) Solid Mechanics: continuum mechanics, fracture mechanics, thermomechanical

behavior in severe environments, aging & lifetime reliability of structures.

4) Dynamics and Control of Processes and Systems: development and use of information

describing system behavior (system models), performance criteria, and theories of control

optimization to achieve the best possible system performance subject to known constraints.

A Scoping Workshop held in December, 1985 confirmed the continued needs for research

in these topical areas. Because of budgetary limitations, the implemented BES Engineering

Research Program is somewhat less broad than the program envisioned above. At present,

equal emphasis is being placed in three carefully selected, high priority research areas;

namely,

1) Mechanical Sciences including fluid mechanics (multiphase flow and turbulence) heat

transfer, and solid mechanics (continuum mechanics and fracture mechanics), but excluding

purely computational efforts.

2) System Sciences including process control and instrumentation, and intelligent systems.

3) Engineering Analysis including nonlinear dynamics, data bases for thermophysical

properties of fluids, modeling of combustion processes for engineering application, and

foundations of bioprocessing of fuels and energy related wastes.

These areas contain the most critical elements of the four topics enumerated above; as such

they are of importance to energy technologies both in the short and long term, and

therefore of immediate programmatic interest. It should be noted that other areas of basic

research important to engineering are monitored elsewhere in BES. For instance,

separation sciences and research on thermophysical properties are among the

responsibilities of the Chemical Sciences Division, while microscopic aspects of fracture

mechanics are in the domain of the Material Sciences Division. As resources permit, other

high priority areas are being added to the Engineering Research Program. Thus, as a result

of previous growth in the program budget an important development took place in the

Engineering Research Program: two major concentrations of research were initiated.
First, a new program was organized at Oak Ridge National Lab dealing with intelligent

machines in an unstructured environment. Some resources are available for coordinated,

more narrowly focussed, related, high quality research at universities and other research

centers. All such activities are supported and administered directly by the Engineering

Research Program, but some coordination of efforts with the ORNL program may prove

useful.

Secondly in FY 1985, a collaborative research effort was started between MIT and Idaho

National Engineering Lab. At present, the collaboration is in two distinct areas: Automated

Welding, and Fracture Mechanics. Collateral, high quality research efforts at other

institutions, including Plasma Process Engineering are supported by the Engineering

Research Program.

In the expectation of a future modest growth of this Program, three International

Workshops on Two Phase Flow Fundamental were held one in September 1985 and the

other in March, 1987. The meetings were used to identify basic research needs in the field

of two phase flow and heat transfer; summary reports of the workshops are available from

the Program Office. The proceedings of the two workshops have been published as

volumes in the series "Advances in Heat and Mass Transfer" (Hemisphere Publishing

Company). A third international workshop held in June 1992 surveyed the status of the

field. The proceedings have been published by CRC Publishing Company, also in the

series "Advances in Heat and Mass Transfer".

Two additional workshops were held during 1988. The first dealt with possible research

opportunities in the field of novel devices using the new high temperature superconductors.

The second addressed research needs for bioprocessing of fuels and energy related wastes.

Reports of both workshops have been published. Additional funds had been provided in

FY 1992 to initiate research in the above mentioned bioprocessing area. Of interest are

relevant studies at the intersection of biology, biochemistry, and chemical engineering.

Another workshop aimed at identifying research opportunities to mitigate the effects of

aging in energy production and distribution systems took place in October 1992. The

proceedings have appeared in Applied Mechanics Reviews.

It should be mentioned too, that some very limited support is available for research on

large scale systems. A report of a workshop on needs, opportunities, and options in this

field is available from Professor G.L. Thompson, Graduate School of Industrial

Administration, Carnegie-Mellon University, Pittsburgh, PA 15213. Also there is some

interest in addressing the basic foundations of advanced manufacturing processes. In this

context 36 three-year (12 per year) doctoral fellowships administered by National Academy

of Science-National Academy of Engineering and National Research Council have been

sponsored.
Research projects sponsored by the BES Engineering Research Program are currently

underway at universities, private sector laboratories, and DOE national laboratories. In

fiscal year 1995 the available program operating funds available amounted to about $15.5

million. The distribution of these funds among various institutions and by topical area is

illustrated on the next page. Project funding levels are mostly in the range of $50,000 to

$150,000 per year. Typical duration of a project is three to four years, with some projects

expected to last as long as ten years or more. The BES Engineering Research projects

stem almost without exception from competitive grant applications. Applications which

anticipate definite results in less than two years are usually referred to the appropriate DOE

technology program for consideration. All those interested in submitting a proposal are

encouraged to discuss their ideas with the technical program manager prior to submission

of a formal proposal. Such discussion helps to establish whether or not a potential project

has a reasonable chance of being funded. The primary considerations for possible support

are the technical quality of the proposal and the professional standing of the principal

investigators and staff. An effort is made to attract first rate, younger research engineers

and energy oriented applied scientists. A high technical caliber of research is maintained

by requiring that the projects supported have potential for a significant contribution to

energy related engineering science, or for an initial contribution to a new energy relevant

technology. Sponsored projects are selected primarily for their relevance to DOE mission

requirements; the contribution to energy related graduate education is an important

consideration. Thus projects sponsored at universities are essentially limited to advanced

theoretical and experimental studies usually performed by faculty members, staff research

scientists, and doctoral candidates.
ENGINEERING RESEARCH PROGRAM

FY '95 BUDGET ($000'S)

BY INSTITUTIONAL TYPE

Y NATIONAL A

M/ LABORATORIES

~/ 33% / \

$5090 / \

(18 Projects) / \

OTHER i /

11%

$2024

(11 Projects)p UNIVERSITIES

\ ^ 560% /

\SYSTEM SCIENCES 4208 8293 /

ENGINEERING ANALYSIS(103 Projects) 53

ENGINEERING RESEARCH PROGRAM

FY'95 BUDGET

BY TECHNICAL AREAS

(S000's) % NUMBER OF PROJECTS

MECHANICAL SCIENCES 4722 30.6 55

SYSTEMS SCIENCES 4208 27.3 24

ENGINEERING ANALYSIS 6479 42.1 53
Table of Contents

University of Alabama ................................ 1

Argonne National Laboratory ................... 1...... 1

University of Arizona .......................... ...... 2

Arizona State University ................ ........... ... 2

Battelle M emorial Institute ............................. 3

Brown University ................ .................. 3

University Of California, Berkeley ........................ 3

University Of California, Los Angeles ..................... 5

University Of California, San Diego ....................... 6

University Of California, Santa Barbara .................... 8

California Institute Of Technology ....................... 9

Carnegie Mellon University .................... ........ 10

University Of Chicago ................................ 11

Clarkson University .................................. 11

Cornell University .............................. .... 12

Dartmouth College ............................. ...... 13

Duke University ............................... 13

Florida State University ..... .................... 14

Georgia Institute of Technology ............. ............. 14

Idaho National Engineering Laboratory .................... 15

University Of Illinois ................... ........... 17

Johns Hopkins University ...... ................. ...... 18

Robert H. Kraichnan, Inc ............................... 19

Lawrence Berkeley Laboratory .................... ...... 19

Lawrence Livermore National Laboratory ................... 19

The Lovelace Institutes ................................ 20

University Of Maryland ........................ ....... 20

Massachusetts Institute Of Technology ..................... 22

University Of Minnesota ............................... 25

National Academy of Sciences/National Research Council ....... 27

National Aeronautics and Space Administration ............... 27

National Institute Of Standards And Technology .............. 27

The City University Of New York, The City College ... ........ 28

State University of New York ....................... ... 30

Northwestern University ............................... 30

University Of Notre Dame ........... .................. 32

Oak Ridge National Laboratory .......................... 33
Table of Contents (continued)

Pacific Northwest Laboratory ....................... 34

University Of Pennsylvania .. ..................... 34

Pennsylvania State University . ....................... 35

Princeton University .... ..... ................... 35

Purdue University ................... ........... 36

Rensselaer Polytechnic Institute ....................... 37

Rice University .. ..... .................... 38

University Of Rochester ....................... 38

Rockefeller University . ........................ .. 39

Sandia National Laboratories ........................ 40

University Of Southern California ....................... 41

Stanford University ............................ 41

University Of Texas At Austin .......................... 44

Tufts University ..... .................... 45

University of Washington ............................. 45

Washington University ........................ 46

Washington State University .......................... 46

University Of W isconsin ......... ... ................... 46
University Of Alabama clarified. Certain deficiencies of well-known

Dept of Mathematics $106,000 evolution equations were pointed out.

Tuscaloosa, AL 35487 01-C

94-3

Hydrodynamic Instabilities and Coherent Argonne National Laboratory

Structures Energy Technology Division $194,411

A. Frenkel Argonne, IL 60439 01-A

94-1

The objective of this research is to further the Chaos in Fluid-Structure Systems

fundamental understanding of stability properties S. Chen

of several far-from- equilibrium fluid systems which

are relevant to energy engineering sciences. In Energy systems have had a history of dynamic

particular, flows periodic in space and possibly in structural instabilities caused by fluid flow resulting

time are studied as models to gain insights into in costly component repair and replacement and

such turbulence phenomena as large-scale loss of energy production. Integrated theoretical

coherent structures, eddy viscosity, and the and experimental studies are being performed to

inverse cascade of energy. Film flows--such as enhance the understanding of nonlinear

core-annular ones--are important to, e.g., oscillations and dynamic instability phenomena

lubricated pipelining of viscous oils. The involving both fluids and solid structures and their

large-scale evolution equations for the different coupling. The objectives are to contribute to the

systems may exhibit common features, such as explanation of observed phenomena, providing

pattern formation and coherent structures. insights into chaotic characteristics of such

coupled mechanical systems and ultimately, to the

Some of the results are as follows: A rigorous solution of engineering design problems. This is

iterative method was suggested for the problems a cooperative research program with Professor F.

of periodic-flow stability. The possibility of negative Moon at Cornell University.

isotropic large-eddy viscosity was demonstrated,

resolving a rather long-outstanding question. A Fluidelastic instability of loosely supported tubes is

weakly nonlinear Landau-type theory was suspected to be one of the main causes of tube

constructed for an intermediate-scale instability of failure in some operating steam generators and

a periodic flow. The spatial structure of the heat exchangers. As a vehicle to understand the

saturated disturbances of this non-uniform flow is nonlinear behavior of fluid-structure systems,

significantly different from previously known, fluidelastic instability of loosely supported tube

uniform cases. arrays in crossflow is being studied in detail. A

tube row with a motion-limiting stop configuration

For film flows, a perturbative method capable of has been tested to investigate various response

yielding both the evolution descriptions and the characteristics and a mathematical model based

parametric conditions of their validity was on the unsteady flow theory has been developed

suggested. A highly nonlinear evolution equation to predict the response characteristics of this

of a wavy flow down a cylinder was obtained. Its classical fluid-structure system. Other fluidnumerical simulations yielded an excellent structure systems, such as coupled stack/wire

agreement with experiments. They also revealed, dynamics due to wind excitations, have also been

for the first time ever in numerical simulations, investigated. It involves lock-in resonance and

irreversible coalescences of soliton-shaped parametric resonance of coupled oscillations of

coherent structures; these are now thought to play guided wires and stack. Analytical results and

an important role in the wave dynamics of film experimental data agree fairly well.

flows. Also, a theory of a flow down an inclined

plane was constructed. Simulations of the Tests and analysis of tube arrays are being

evolution equation showed a remarkable continued. One of the key elements is the motionagreement with three-dimensional wave patterns dependent fluid forces which are being measured

observed in recent experiments. using the existing water channel with an emphasis

on the nonlinear behavior. The motion-dependent

Some fundamental questions concerning fluid forces depend on Reynolds number, reduced

commonly used perturbative approaches were flow velocity, and oscillation amplitude. Specific

Engineering Research 1 1995
topics being addressed include mathematical states in mechanical response of brittle and quasimodels and instability mechanisms, interaction brittle solids containing a large number of crackbetween flow field and oscillating structures, useful like micro-defects. More specifically, the focus of

applications of fluidelastic instabilities, and control the ongoing research is placed on the

of fluid/structure systems. determination of circumstances (type of loading,

confinement level, shape and size of the

specimen, thermal and environmental conditions,

University of Arizona etc.) leading to the onset of critical states defined

Aerospace & Mechanical Eng $138,875 as a threshold connectivity at which a solid ceases

Tucson, AZ 85721 01-B to support external loads.

93-3

Film Cooling in a Pulsating Stream Technical Approach: Current applied mechanics/

i. Wygnanski, H. Fazel, A. Ortega engineering practice in evaluating the mechanical

failures of brittle and quasi-brittle solids

Turbulent wall-jets are used for boundary layer emphasizes use of effective continuum theories

control and film cooling. Thus the present coupled with the deterministic and highly idealized

investigation endeavors to determine the effects of description of the defect geometry (such as doubly

two-dimensional excitation on skin friction and heat periodic arrays of penny-shaped cracks). In

flux in laminar and turbulent wall-jets. The contrast, the approach selected in this research

approach includes experiments, numerical program accentuates the stochastic geometry of

simulations, and stability theory. The theoretical the microstructural disorder and its effect on the

analysis at either constant temperature or constant onset of macro-fracture and the type of the failure

heat flux boundary conditions was completed and mode.

validated experimentally in laminar flow. The

development of the code for the compressible One of the important aspects of this research is to

D.N.S continued. The code is based on the explore applicability of the novel methods of

complete compressible Navier Stokes equations in statistical physics (percolation theory, models of

conservation formulation. The wall boundary self-organized criticality, etc.) to micromechanical

condition for the temperature was changed to models. Some of the alead obtained results

allow for partially cooled or heated walls, where provide connection between the mechanical

the length of the temperature ramp can be parameters such as stiffness and damage variable

specified. The experimental investigation included and the percolation theory concepts such as the

simultaneous measurements of mean and order parameter, excluded volume, etc.. This

fluctuating components of velocity and temperature provides a set of rational criteria for the selection

using hot and cold wire anemometers. The flow of the universal dimensional invariants needed to

was subjected to controlled two-dimensionalo describe the onset of a certain class of failures.

excitation. Experimental results for the laminar Secondly, use of the statistical methods (such as

wall-jet show that moderate excition may result in factal and multiractal formalism) provide a

skin friction of 60% and a concomitant increase in superior and size-independent (intrinsic)

heat flux of 30%. description of the fluctuations in the stress field

(stress concentrations) in the vicinity of the critical

states. This aspect alone should provide a

Arizona State University definitive answer related to the dependence of the

order-disorder transition on the microstructural

Mechanical & Aerospace Eng $50,945 texture and/or boundary conditions. In summary,

Tempe, AZ 85287 01-A the selected approach provides the best hope of

92-4 description of the universal aspects of the

Contiuum Damage Mechanics - Critical States stochastic nature of the damage and its evolution

D. Krajcinovic in the vicinity of the critical state.

Objective: Primary objective of the current

research program is to examine a variety of critical

Engineering Research 2 1995
Battelle Memorial Institute measurable features of the microstructure of those

Engineering Mechanics Dept $23,000 materials. The motivation for doing so is to

Columbus, OH 43201-2693 01-A establish which material and/or geometric

94.3 characteristics account for macroscopic failure,

An Investigation of History-Dependent with a view toward improvement of failure

Damage In Time-Dependent Fracture resistance through material selection or

Mechanics microstructural design. Such calculations

F. Brust, Jr. normally require construction of simple, conceptual

models and numerical simulation of more complex,

To increase energy efficiency, new power plants realistic models. In the present project, this is

must operate at higher and higher temperatures. viewed as a modeling issue; existing

Moreover, power generation equipment in the US computational procedures will be applied as tools

continues to age and is being used far beyond its to extract quantitative interpretations for the

intended life. Some recent failures have clearly models developed. The emphasis will be on the

illustrated that current methods for insuring safety behavior of structural metallic alloys with moderate

and reliability of high temperature equipment is to high ductility. Thus, the dominant mechanism

inadequate. Because of these concerns, an of plastic deformation is crystallographic slip and

understanding of the high-temperature crack material strength degrades through nucleation,

growth process is very important. growth and coalescence of micro-voids. Plastic

strains in such processes can be large so that

Critical experiments are performed on materials strain localization issues become important in the

which are used in these severe high temperature analysis of models. Finally, the models will allow

environments. Theoretical models are then for a complete loss of stress carrying capacity of

developed which attempt to predict the crack the material associated with the creation of new

growth and failure response of these material surface, without the introduction of an additional

components. The models are then exercised, and failure criterion, so that fracture can arise as a

compared to the experimental results, with natural consequence of the deformation process.

modifications/improvements made as necessary.

This synergistic interaction between analytical,

computational, and experimental disciplines has University Of California/B

proven very effective. To date, both sustained and Dept of Chemical Engineering $78,440

variable high temperature load histories have been Berkeley, CA 94720 06-A

investigated in two-dimensional geometries. The 94-4

model, which is based on the use of advanced Enzyme Adsorption and Activity at Liquidconstitutive laws and the use of new integral Liquid Interfaces

parameters to understand and predict the events H. Blanch

leading to failure, has proven quite effective.

Current efforts involve investigating different Protein adsorption at oil/water interfaces is the

histories, and investigating three-dimensional primary phenomenon governing formation of

effects, the latter of which is realistic for service stabilized emulsions. The homogeneity of the

conditions. liquid/liquid interface provides an ideal

environment to examine the fundamental forces

involved in protein adsorption and film formation.

Brown University The approach taken in this study involves two

Dept of Chemical Engineering $98,919 experimental techniques: pendant drop

Providence, RI 720 01-A tensiometry and total internal reflection

95-3 fluorescence spectroscopy (TIRFS). The

Simulation and Analysis of Dyanmic Failure combination of these two techniques allows

of Ductile Materials investigation of protein adsorption dynamics as

L.B. Freund well as providing insight into the structure of

adsorbed proteins. Pendant drop tensiometry is

A central goal in the mechanics of materials is the used to follow dynamic interfacial tension of

calculation of parameters which characterize several well-characterized proteins under

macroscopic failure of materials in terms conditions of varying protein bulk concentration,

Engineering Research 3 1995
pH, ionic strength, and oil phase characteristics. solved analytically and matched to an

Surface tension measurements have been electropositive edge plasma. The solutions are

employed to monitor protein adsorption, as well compared to a simulation of a parallel-plane r.f.

as measure the relevant time scales for driven oxygen plasma and found to give good

adsorption. An analysis of unique systems such as agreement, provided the two-temperature electron

disulfide-reduced proteins and short chain distribution found in the simulation is also used in

poly-amino acids is being undertaken to reveal the the model. The results indicate the need for

magnitude of non-native bond formation and determining a two-temperature electron distribution

primary structure on adsorption and gelation self-consistently within the model.

behavior. We have constructed a liquid/liquid

TIRF spectrometer. This apparatus enables

quantitation of protein adsorption, and permits University Of California/B

changes in the protein secondary structure to be Dept o Mechanical Engineering $96,460

observed based on the intrinsic fluorescence of Berkeley, CA 94720 01-B

tryptophan residues. Initial studies using TIRFS 95-3

have shown shifts in the fluorescence emission Ultrashort Laser Heating and Phase

spectra of fluorescein conjugated to lysozyme Change in Liquids

upon adsorption to a heptane/aqueous phosphate C.-L. Tien

buffer solution, indicating the extent of

conformational change of the adsorbed protein. The general objective of this research program is

to achieve a better understanding of the

fundamental mechanisms of thermal radiation and

University Of California/B heat conduction in microscale structures

Dept of Electrical Engineering $90,000 commonly encountered in engineering

& Computer Sciences 06-C applications.

Berkeley, CA 94720 93-3

When the pulse duration of short-pulse, high

Dynamics of Electronegative Plasmas for power lasers approaches the characteristic

Materials Processing molecular time scales of the material with which

A. Lichtenberg, M. Lieberman the laser interacts, traditional models of radiation

absorption and energy transport must be

The purpose of this project is to study the re-examined. A complete understanding of heat

equilibrium particle and energy balance and the generation and dissipation during this process is

heating mechanisms in electronegative r.f. required for precise, efficient laser processing.

discharges. Particular attention is given to the The research of the past year has resulted in

formation of non-Maxwellian electron distributions microscopically based models of radiation

and their effect on the macroscopic parameters. absorption and thermal transport in liquids,

The research includes theoretical, particle-in-cell semiconductors, and disordered media. These

simulation, and experimental investigations. The models have been applied to create novel

sheath heating theory and the simulation results solutions to important engineering problems.

developed for electropositive plasmas are used to

guide the investigations. The investigation The model for liquids was developed to include

includes, but is not limited to, the study of oxygen consideration of the short time-scale phenomena

feedstock gas in capacitively coupled, parallel of saturable absorption and multiphoton absorption

plate, r.f. discharges. in energy transport calculations. The multiphoton

effect was proposed as a novel mechanism for

A macroscopic analytic model for a three- imparting large amounts of energy into normally

component electronegative plasma has been transparent liquids. Experiments were performed

developed. Assuming the negative ions to be in to confirm model predictions. Fractal theory was

Boltzmann equilibrium, a positive ion ambipolar applied to examine short-time-scale energy

diffusion equation is found. The electron density transport in random media. On short time scales

is nearly uniform, allowing a parabolic anomalous diffusion was predicted due to the

approximation to the plasma profile to be disorder. Finally, using predictions from models of

employed. The resulting equilibrium equations are femtosecond (10-15 s) laser interactions with

Engineering Research 4 1995
semiconductors, a new method of releasing failed transfer devices by selecting the surface

microstructures through electronically-induced characteristics that yield high heat transfer and low

desorption of water was developed and pressure drop. Flow across or through bundles of

demonstrated. roughened tubes is presently being modeled.

University Of California/LA University Of California/LA

Mech, Aero & Nuclear Eng Dept $ 0 Mech, Aero & Nuclear Eng Dept $110,559

School of Eng & Applied Science 01-C School of Eng & Applied Science 06-C

Los Angeles, CA 90024-1597 92-3 Los Angeles, CA 90024 93-3

Basic Studies of Transport Processes in Linear Kinetic Theory and Particle

Porous Media Transport in Stochastic Mixtures

I. Catton G. Pomraning

The objective of this project is to develop an The goal in this research is to develop a

understanding of the governing physical processes comprehensive theory of linear transport/kinetic

at a level appropriate for development of theory in a stochastic mixture of solids and

macroscopic models for use in the analysis of immiscible fluids. Such a theory should predict the

engineered energy systems. Current work ensemble average and higher moments, such as

considers both single-and two-phase flows. Efforts the variance, of the particle or energy density

are both theoretical (numerical in some cases) and described by the underlying transport/kinetic

experimental. Emphasis is placed upon the equation. The statistics to be studied correspond

development of mathematical models for single- to N-state discrete random variables for the

and two-phase turbulent transport in highly porous interaction coefficients and sources, with N

media with regular, non-uniform, isotropic and denoting the number of components in the

non-isotropic characteristics. The basis of the the mixture. The mixing statistics to be considered

work is a hierarchial heterogeneous medium are Markovian as well as more general statistics.

averaging methodology using fully turbulent

models with Reynolds stresses and fluxes in every In the absence of time dependence and scattering,

pore space building from the lowest level. the theory is well developed and described by the

Boundary and interphase conditions are master (Liouville) equation for Markovian mixing,

incorporated at various scales leading to and by renewal equations for non-Markovian

descriptions of momentum, heat and mass mixing. The intent of further work is to generalize

transport in porous media. Equations for these treatments to include both time dependence

developed flow and diffusive processes in a and scattering. A further goal of this research is to

random, highly porous medium have been develop approximate, but simpler, models from the

developed along with the statistical and numerical comprehensive theory. In particular, a specific

methodology needed to treat the fluctuation terms goal is to formulate a renormalized transport/

for various assigned random porous morphologies. kinetic theory of the usual nonstochastic form, but

Models have been developed to describe turbulent with effective interaction coefficients and sources

flow, diffusion of admixtures, and energy to account for the stochastic nature of the probprocesses in highly porous media. Using second lem. Numerical comparisons of all models will be

order turbulent models, equation sets have been made against Monte Carlo simulations which

obtained for laminar and turbulent filtration and involve a straightforward average of solutions for

two-temperature or two-concentration diffusion in a large number of physical realizations of the

non-isotropic porous media and interphase statistical mixing. Contact will also be made with

exchange and micro-roughness. The equations experimental simulations of cloud-radiation interdiffer from those found in the literature. The actions currently underway at another institution as

models are being used to optimize some heat part of DOE's global climate modeling initiative.

Engineering Research 5 1995
University Of California/LA concept of unfolding the attractor using the method

Physics Dept $77,396 of global false nearest neighbors and then

Los Angeles, CA 90024 06-C determining locally the number of dynamical

93-3 degrees of freedom using the local version of this

Nonlinear Waves in Continuous Media has brought to the study of complex behavior a

S. Putterman robustness which allows it to be used in

engineering analysis and design. The algorithms

Nonlinear wave interactions in far off-equilibrium developed for this purpose have also been used in

fluids are being studied with the goal of a variety of applications requiring the separation of

understanding the interplay between processes a chaotic signal from another information bearing

that concentrate energy (e.g. sonoluminescence), signal or noise'. The tool kit of these algorithms

randomize energy (e.g. wave turbulence) and form is being ported to a common interface for use in

localized states (e.g. solitons). The experimental the energy related sciences.

discovery that strong sound waves generate

picosecond flashes of light is now being studied

from the theoretical perspective with the goal of University Of California/SD

understanding how energy can focus by twelve Dept of App Mech & Eng Sci $127,070

orders of magnitude. Turbulence in nonlinear La Jolla, CA 92093 06-B

waves is being studied from both the theoretical 93-3

and experimental directions. Goals include the Fundamental Studies of Spray Combustion

development of a Fokker-Planck theory that P. Libby, F. Williams

includes intermittency as well as the observation of

collective modes in turbulence that are analogous This research involves a combined experimental

to second sound. High amplitude waves can also and theoretical effort related to the behavior of fuel

form self-localized states such as the breather and droplets in well defined but nonuniform flows. A

kink solitons, and domain walls which have test rig which permits a wide variety of

recently been observed. Current efforts are aimed investigations including nonpremixed, premixed

at extending these findings to systems which are and partially premixed systems in both laminar and

two- and three-dimensional. This work proceeds turbulent streams represents the main

from the experimental, analytical and simulational experimental setup. A phase doppler particle

avenues of approach. analyzer which permits measurement of two

velocity components, droplet diameter and number

density is the principal instrumentation employed

University of California/SD in our studies. It is supplemented by a gas

Scripps Inst of Oceanography $0 chromatograph for measuring species

La Jolla, CA 92093-0402 06-C concentrations. We have nearly completed and

94-4 are writing up for publication our theoretical and

Broadband Signals: Signal Processing experimental research on droplet oscillation in

in Chaos opposed streams, behavior which accounts for the

H. Abarbanel observed bimodality of the probability density distributions of the axial velocity. Experiments on

The analysis of chaotic signals observed in a turbulent spray impinging on a wall and

measurements on physical systems is of complementary theoretical analysis lead to

importance in energy problems ranging from estimates of the largest droplets which follow the

fluidized bed flows in fossil energy applications to gas including fluctuations and the smallest droplets

determination of the natural climate variability to which ignore velocity fluctuations. When these

the uncovering of simple models for complex experiments are repeated for a wall of suitably

behavior in fluid flows. This research has high temperature, a trimodal distribution of axial

developed tools for this analysis which allows one velocity is observed; the implication is that droplets

to reconstruct the multivariate state space of a of appropriate size impinge on the wall, bounce

system from observations, time lagged, of a single back and retur a second time. At lower wal

dynamical variable. The time delay, the temperatures entirely different behavior is

dimension, and properties of the strange attractor observed, namely droplet breakup. Our recent

can all be determined from these data. The work concerns water sprays in a two stage

Engineering Research 6 1995
homogeneous flame in order to investigate the University Of California/SD

removal of the CH-radical by water. Preliminary Inst for Nonlinear Science, R-002 $101,185

results on this study were presented at the 31st La Jolla, CA 92093 06-C

AIAA Propulsion Conference. Additional 93-3

experiments on this flow are underway. Structure of Turbulence, Conditional

Averaging and Subgrid-Scale Modeling

E. Novikov

University Of California/SD

Dept of Chemistry, 0340 $ 0 Well developed turbulent flows are encountered in

La Jolla, CA 92093 06-C many energy engineering enterprises, as well as

92-4 in environmental, aerospace and naval

Noisy Nonlinear Systems engineering. The number of degrees of freedom

K. Lindenberg for such flows is enormous and direct numerical

simulations (DNS) are impossible now and in the

The broad objective of this project is to investigate foreseeable future.

the interplay of nonlinear deterministic dynamics

with spatial and temporal fluctuations. One of the major goals of this project is to

advance the knowledge of the structure of

Density fluctuations in binary reaction--diffusion turbulence, aiming it at a subgrid-scale modeling

processes in low dimensional systems lead to for the large-eddy simulations (LES).

spatial and temporal anomalies. We have

extended our mesoscopic approach to obtain the The developed approach for achievement of this

reaction-diffusion equations that are customarily goal includes: conditional averaging of the

postulated phenomenologically to a broader variety Navier-Stokes equations (NSE); use of Markov

of systems. This approach places a number of processes with dependent increments (consistent

theories on a common fundamental basis. with NSE); breakdown coefficients and associated

infinitely divisible probability distributions.

We have begun an investigation into the

characteristic manifestations of soft anharmonicity Among the obtained results are: probability

in nonlinear coupled arrays both in and out of distribution for three-dimensional (3D) vectors of

thermal equilibrium. In particular, we are velocity increments, which has an unusual form

interested in various ways in which vibrational and experimentally observed exponential

energy may become spontaneously localized as a asymptotics; new scaling for experimentally and

consequence of anharmonicity even in numerically observed 3D "vortex strings", 2D

translationally invariant arrays. These include the coherent vortices and coherent structures of scalar

overpopulation of anharmonic vibrations in thermal fields; exponential behavior of conditionally

equilibrium, the inhibition of dispersion, and the averaged vortex stretching as a function of fixed

enhancement of spatial coherence. vorticity, which is obtained by DNS on a CM-5

parallel computer, using 6th-order finite differences

We have continued our work on a microscopic on (256)3 grid; the whole 3D conditionally

quantum mechanical model for charge transfer in averaged vorticity field, obtained by DNS;

condensed media. We are able to calculate the statistical characteristics of microcirculations;

reorganization energy and rate prefactor as a probability distributions and moments of the

function of elementary parameters for some simple breakdown coefficients (intermittency), compared

model situations. with experimental data for the Taylor-scale

Reynolds number 3200; a hierarchy of

subgbrid-scale models, preliminary tested by DNS

and by LES for isotropic, shear-flow and

free-surface turbulence.

Engineering Research 7 1995
University Of California/SD University Of California/SD

Dept of Physics $115,000 Institute of Nonlinear Science $99,990

La Jolla, CA 92093 06-C La Jolla, CA 92093-0402 06-C

93-3 95-3

Traveling-Wave Convection in Fluid Mixtures Modeling of Process Control

C. Surko L. Tsimring

This research program involves the study of Traditionally, for ease of operation and analysis,

convection in fluid mixtures of ethanol and water, technological systems (manufacturing systems,

in which the fluid motion takes the form of communication systems, etc.) have been designed

traveling waves. It is a model system for studying to behave in as linear a manner as possible.

nonequilibrium traveling-wave phenomena that can Increasingly tight specifications, environmental

provide important insights into the behavior of considerations and economic pressures are

double diffusive systems in which the transport pushing the operational windows into regions

occurs on two different time scales. In this where assumptions of linearity tend to break down.

system, the coupling of the concentration field to Despite a flurry of activity in the area of nonlinear

the velocity and temperature fields results in a dynamical systems (both analysis and control

wide variety of potentially important phenomena. system design) we see very few applications of

As a fluid dynamical system, it is closely related to these new results. One important reason is the

atmospheric and oceanographic flows, and as a lack of suitable nonlinear dynamic models. The

model for traveling-wave dynamics, it can provide objective of this project is the development of tools

insights which are useful in the understanding of for building nonlinear models based on

other traveling-wave systems such as input/output data from systems which may exhibit

large-aspect-ratio lasers. chaotic or nonchaotic dynamics, to implement the

algorithms in efficient software packages and to

Earlier experiments in an annular geometry, which apply them to a wide range of examples, primarily

is essentially a one-dimensional system with from communications and process control. These

periodic boundary conditions, led to a basic examples are not just academic test cases which

understanding of the dynamics of uniform and provide feedback on the direction of the theoretical

confined states of traveling waves. Current developments, but constitute by themselves

experiments involve a large aspect-ratio important technological problems. The varied

two-dimensional convection cell which allows study background of the investigators, the

of the role of defects and grain boundaries in the interdisciplinary approach, and the emphasis on

development of traveling wave patterns. States of tools, software andapplications hold high promise

intense spatio-temporal disorder can be created for a broad impact of the proposed research. This

which consist of many small domains of plane is a joint projects with M. Morari at the California

waves. As the pattern evolves in time, the Institute of Technology.

domains grow until the average domain size is of

the same order as that of the convection cell.

Thus, the initially homogeneous "turbulence" gives University Of California/SB

way to a pattern consisting of a few large Dept of Physics $135,000

traveling-wave domains separated by stable Santa Barbara, CA 93106 06-C

domain walls. One basic question to be 93-5

addressed is whether the model equations Bifurcations and Patterns in Nonlinear

commonly used to describe this system can Dissipative Systems

reproduce the transition from the disordered initial G. Ahlers, D. Cannell

state to the ordered multi-domain state. Numerical

algorithms have now been developed for This project consists of experimental investigations

characterizing these multi-domain states, and they of heat transport, pattern formation, and bifurcation

allow direct comparisons between the phenomena in non-linear non-equilibrium fluidexperimental patterns and analytical models. mechanical systems. These issues are studies in

These analysis tools are also likely to prove useful Rayleigh-Benard convection, using both pure and

in studying traveling-wave patterns in other multicomponent fluids. They are of fundamental

physical contexts. scientific interest, but also play an important role in

Engineering Research 8 1995
engineering, materials science, ecology includes both experimental and computational

meteorology, geophysics, and astrophysics. For components (using direct numerical simulation). In

instance, various forms of convection are this work, the effects of waves on turbulence in a

important in such diverse phenomena as crystal liquid stream is investigated. The study includes

growth from a melt with or without impurities, two-and three-dimensional waves, with and without

energy production in solar ponds, flow in the imposed wind shear. Wind flow can be either coearth's mantle, geo-thermal stratifications, and or counter-current to the liquid. The study is

various oceanographic and atmospheric experimental, using a 3-D LDA synchronized with

phenomena. Our work utilizes computer- acoustic surface position measurements (both non

enhanced shadowgraph imaging of flow patterns intrusive). These are also synchronized with

and high-resolution heat transport measurements. high-speed video flow visualization using

microbubble tracers. Wire gauges are also used

We studied convection in a gas (CO2) under for detecting wave length. The waves are

pressure (about 30 bar) in a very large aspect generated mechanically.

ratio sample (radius/height = 150). Under nonBoussinesq conditions, the bifurcation from Results indicate that the turbulence intensity away

conduction to convection became hysteretic, and from the wall channel bottom-wall was

the initial pattern consisted of a perfect lattice substantially increased as a result of the waves.

containing more than 104 hexagonal cells. For The increase appears to be a consequence of

parameter values where time-independent parallel turbulence production in the outer flow region

straight rolls were theoretically predicted for a since the turbulence intensity in the wall region

laterally infinite system, we found a state of spiral- was not altered, and it seems that the turbulence

defect chaos. wall structures were not affected as well. This, in

spite of the fact that the wave-induced orbital

We investigated convection in a nematic liquid motion reached all the way to the wall. Even in

crystal in a horizontal magnetic field H. We found predominantly laminar flows, the introduction of

excellent agreement with recent theoretical 2-D waves causes three-dimensional turbulence in

predictions for the bifurcation line R,(H), and for the near-free surface region. Turbulence

the convection-roll orientations as a function of H. enhancement in this region is in general found to

We also used this system to study convection be proportional to the wave strength. The next

when two phases (the nematic and isotropic phase of the work will focus on the combined

phase) are present in the cell. Convection in the effect of wind and waves on the turbulence

presence of a first-order phase change is relevant structure.

to convection in the earth's mantle; ours are the

first quantitative experiments relevant to this

important problem. California Inst Of Technology

Chemical Engineering 210-41 $125,000 We have continued our work on binary-mixture Pasadena, CA 91125 03-A

convection. For positive separation ratios 4T we 91-3

studied square patterns. For negative A, we Modeling for Process Control

investigated time formation of localized pulses in M. Morari

two dimensions.

While many advanced analysis and synthesis

techniques have been recently developed for the

University Of California/SB control of nonlinear systems, few of these results

Dept of Chemical & Nuc Eng $107,400 have been utilized in process applications. One

Santa Barbara, CA 93106 01-C key reason may be the lack of suitable models for

95-3 these systems. The objective of this research

Wave Turbulence Interactions program is the development of tools for building

S. Banerjee nonlinear models based on input/output system

data and the implementation of these tools in an

The work is part of an ongoing research effort efficient software package. The toolkit is

aimed at understanding transport processes specifically intended to assist in problems of

across a gas-liquid interface. The research nonlinear estimation and control, and monitoring

Engineering Research 9 1995
and diagnostics, tasks which can be interpreted as ductile metals is inherently three dimensional (e.g.,

"model validation". shear lips, tunneling) and it is necessary to

develop adequate modeling tools to understand

Currently, the modeling methods being examined such phenomena and develop models predicting

are similar to those which have shown great such behavior.

success in the identification of self-driven systems.

For example, the method of False Nearest

Neighbors (FNN) was first developed to determine Carnegie Mellon University

the dimensionality of autonomous chaotic systems. Chemical Eng Dept $151,854

The FNN method has been extended in order to Pittsburgh, PA 15213 03-A

determine the dimensionality of systems from 94-4

properties of input/output data. Methods are also Systematic Process Synthesis and Design

being developed for determining the proper Methods for Cost Effective Waste

sampling time of a nonlinear input/output system. Minimization

Determining a proper sampling time and model L Biegler, I. Grossmann, A. Westerberg

order are necessary first steps for building

accurate low order models. This effort is This project is developing a novel integrated

coordinated with L. Tsimring at U.C.-San Diego. approach for process synthesis and design to

address recent environmental challenges. The

approach provides rigorous trade-offs among raw

California Institute Of material and energy costs, capital investment and

Technology waste treatment. Issues of waste minimization

Graduate Aeronautical Laboratories $99,664 addressed include:

Pasadena, CA 91125 03-A

a95 3 1. Economic design of reactor networks that

Dynamic Failure Characterization minimize conversion of raw materials to waste

of Ductile Steels byproducts.

A. Rosakis

2. Synthesis of separation sequences to isolate,

To aid in the design and vulnerability analysis of redirect and recycle byproducts.

energy systems (e.g., pressure vessels, pipelines,

reactors), it is necessary to monitor and quantify Integrated synthesis and design of reaction,

the mechanical behavior and failure modes of separation and energy systems with environmental

materials used in such systems under carefully and operability concerns, also dealing with process

controlled conditions. Because of design uncertainty.

constraints and safety issues, energy systems are

typically built with corrosion resistant and highly Supeior reactor designs can have the greatest

ductile metallic alloys such as stainless steels. impact for process improvement, both from an

However, due to aging of such structures in the environmental and an economic perspective. A

energy industry, it is essential to understand the quantitative targeting approach for reactor

effect of embrittlement, ductile-brittle transition and networks is permitting the reduction of waste

its influence on the resistance to catastrophic byproducts at the source. The second task

failure, i.e., crack initiation and unstable growth concentrates on the synthesis of flexible

Relatively little is known regarding dynamic crack separation processes (displaying azeotropic and

initiation and growth in ductile metals. A major liquid/liquid behavior) - with efforts to overcome

challenge which has remained unresolved in this the combinatorial explosion of alternatives, each of

area is the measurement of J-integral under a which requires a very large and difficult

combination of large scale yielding conditions and optimization be solved. The third task combines

dynamic loading. However, recent advances in structural optimization and problem decomposition

high-speed diagnostic techniques and at various modeling levels in order to screen

computational capabilities has made it possible to alternatives based on economic, environmental

investigate and and develop a fundamental a fundamental and operabilty trade-offs, before complex

understanding of dynamic failure in ductile simulation models are applied. This approach also

materials such as stainless steels. Failure in such incldes the development of flexible designs that

Engineering Research 10 1995
are tolerant to uncertainties related to process University Of Chicago

conditions and waste treatment requirements. The Enrico Fermi Institute $165,000

Chicago, IL 60637 06-C

Carnegie Mellon University 93-3

Dept of Elec & Comp Eng $0 Fundamentals and Techniques of

Pittsburgh, PA 15213 03-C Nonimaging Optics

92-3 R. Winston

Research on a Reconfigurable and Reliable

Manipulators Nonimaging optics departs from the methods of

P. Khosla, T. Kanade traditional optical design to develop instead

techniques for maximizing the collecting power of

The goal of our research is to develop basic concentrating elements and systems. Designs

design theory and methodology that will allow one which exceed the concentration attainable with

to determine both the kinematic and dynamic focusing techniques by factors of four or more and

configuration of a manipulator capable of approach the theoretical limit are possible. Our

performing a given task. The motivation for this theoretical work on nonimaging designs has led to

arises from the concept of a modular manipulator our group experimentally demonstrating ultra-high

system comprising a set of link and joint modules flux from sunlight which exceeds previous results

of various sizes which may be assembled together by substantial factors. In 1991 we presented the

in a desired kinematic configuration to achieve a proposal that nonimaging designs be regarded as

specific task. The joint and link modules have functionals of the desired irradiance, rather than

consistent mechanical and electrical interfaces depending on a static parameter such as the

which will allow either semi-skilled field personnel "acceptance angle". The working out of this

or another manipulator to rapidly configure a "tailored edge ray " algorithm has led to many

manipulator to meet specific task requirements. applications in illumination and flux concentration.

Since current manipulator systems are of fixed Current algorithms under study employ methods

configuration, they lack the ability to perform from non-local optimization as well as application

widely varying tasks. Further, these manipulators of Lorentz geometry to flow-line designs.

are not fault tolerant - a loss of a degree-offreedom will result in a significantly reduced

capability to perform the task it was deployed for. Clarkson University

In pursuing research on a reconfigurable modular Dept of Chemical Engineering $63,125

manipulator system, our goal is to not only to Potsdam, NY 13676 01-C

create the technology but to push basic research 94-3

for design of non redundant, redundant, and fault Gas and Solids Holdup in Three Phase

tolerant manipulators. Bioreactors

J. McLaughlin This basic research effort will address the problem

of mapping tasks into a manipulator configuration, The goal of this research is develop mathematical

formulation of control algorithms for the mapped modeling and tools that can lead to a better

configuration, and experimental verification of the understanding of three phase Bioreactors.

developed ideas. Though it is not the primary Fluidized beds that use gel beads containing

objective, we believe that building prototype bacteria are of particular interest. The bead

experimental modules for demonstrating our ideas Reynolds numbers are order unity. Thus, models

will also contribute to the technology of modular developed for particle Reynolds numbers that are

manipulators. For configuring a manipulator from large compared to unity do not correctly predict

task requirements, we have developed the hydrodynamics of the Bioreactors.

methodologies that map the task requirements into

a specific non-redundant manipulator. The A goal of the project is to understand the

kinematic task requirements are used to determine interaction between gas bubbles and gel beads. A

the link lengths and the orientation of the modules. fluidized bed has been constructed and used to

The dynamic task requirements are translated to measure the rise velocity of air bubbles.

obtain the sizes and rating of the actuators or

joints.

Engineering Research 11 1995
Translucent (bacteria free) gel beads make it points with a continuous set of fractal dimensions.

possible to study bubble trajectories at solids Our observations of multifractal behavior were, we

volume fractions up to 50%. An effective viscosity believe, the first to be observed in fluid-structure

model based on the Thomas correlation appears vibrations.

to be useful for the bubble size range of interest.

In January 1992, Mr. George Muntean visited

A computer simulation program is being used to Argonne National Laboratory and reported to Dr.

simulate axisymmetric flow around an isolated S.S. Chen our findings on muiltifractal

bubble. It incorporates the effects of surfactants on measurements. He subsequently presented a

the bubble motion. The simulations agree with paper at the DOE Grantees meeting this past

published studies of bubble motion in both pure spring. A revised paper has been submitted to the

and impure water. The simulation program will be Journal of Fluids and Structures, and is currently

used to simulate bubble motion in the fluidized bed under review.

using the effective viscosity model to describe the

effect of the beads. ii) The design of the cross-flow, tube row

experiment began last summer and was

completed this fall. These experiments parallel the

Cornell University work of Cai and Chen (1992). In the Cornell

Mechanical & Aerospace Eng $79,012 experiments the center tube of a five-tube set

Ithaca, NY 14853 01-A suspended on a flexible rod. The tube motion is

94-3 limited by motion stops, thus introducing a strong

Nonlinear Dynamics of Fluid-Structure nonlinearity in the tube stiffness. Preliminary

Systems experiments were carried out in water. The

F. Moon vibration amplitude versus flow velocity shows the

instability onset (Hopf bifurcation) and the vibration

Two principal experiments were carried out under saturation when the impact constraints limit the

this grant during the second year of this project: chaotic motion. This response was found to

depend on whether the flow velocity was

i) Forced vibration of a single flexible tube with increasing or decreasing.

internal flow and ii) Cross flow measurements of

chaotic vibrations of a flexible tube in a five tube The vibration frequency was found to depend on

row. the flow velocity. There is some evidence that the

periodic motion at the onset of flutter to chaotic

i) In the first set of experiments, begun in the first motion transition occurs through quasiperiodic

year, we explored multifractal phenomena, which vibration.

describe the transition from quasiperiodic to

chaotic vibrations. Quasiperiodic vibrations were At the present time we are carrying out the

observed in earlier experiments by Dr. G. Scott calculations of the fractal nature of the Chaotic

Copeland in flow through a long tube with an end motion with the goal of establishing the low

mass. These results were reported an a Ph.D. dimensional nature of the dynamics. At the same

dissertation in Summer 1990. By introducing a time we will correlate our findings wth a similar

periodic-forcing of the tube in an adaptation of this experiment at Argonne National Laboratory to

experiment, we were able to more easily study establish the validity of the fractal dimension

this transition from quasiperiodic to chaotic technique in determining chaos in such flows. The

vibration. This study was motivated by work in the next stage of this work will involve experiments in

mid 1980's on forced Rayleigh-Bemard flow which cross flow of air past a row of tubes as described

showed a linkage between quasiperiodic motion in the next section on our proposed research for

and the circle map. the third year of this project.

In the forced tube experiment we were able to In 1993 a new wind tunnel facility has been

show a similar connection to the circle map, and in constructed and we are investigating nonlinear

particular, the multifractal nature of the breakup of dynamics of a tube row in cross flow.

the torus in c phase space. A multifractal is a

distribution function which is described by a set of

Engineering Research 12 1995
Cornell University Dartmouth College

Sibley School of Mech & Aero Eng $107,061 Thayer School of Engineering $114,726

Ithaca, NY 14853 01-C Hanover, NH 03755 01-C

94-3 95-3

Experimental Studies of Reynods Number Two-Phase Potential Flow

Dependence of Turbulent Mixing and G. Wallis

Transport

Z. Warhaft The objective is to develop a mature science of

two-phase potential flow, based on fundamental

Our experimental studies of the structure of hydrodynamic theory and tested by experiment.

turbulence and its mixing properties are motivated

by a desire to better understand the fluid A theory has been developed for the force on any

mechanics of chemical reactions, combustion and object, in an inviscid flow with weak vorticity, in

environmental pollution. terms of the added mass tensor for the object.

Measurements of the force on a set of streamlined

Turbulence in machinery (such as jet engines and objects in a shear flow agree with the form of the

combustion chambers), and in the environment theory but with coefficients that are 20 to 30%

(the atmosphere and oceans), occurs at high lower than the corresponding added mass

Reynolds numbers, RA. Basic phenomenological coefficients.

models of turbulence are constructed under the

assumption that R. is high. Yet one of the A "particle-pressure coefficient" has been derived

greatest difficulties, both experimentally and for rectangular arrays of spheres moving relative

computationally, has been in generating an to an inviscid irrotational fluid. The coefficient is

isotropic turbulent field of high R;. Thus positive for all aspect ratios in contrast to negative

fundamental theory has not been tested under coefficients predicted by Geurst's equations.

controlled laboratory conditions (although there is

broad confirmation from (uncontrolled) Methods have been developed for predicting the

environmental measurements). Using a novel dipole moment (polarization) of spheres with any

active grid approach devised by Makita of motion in a potential flow. This leads to

Toyohashi University, we have achieved an RA of approximate constitutive equations for the

450, nearly an order of magnitude higher than is two-phase suspension.

typically achieved in conventional isotropic (grid)

turbulence experiments. We are in the process of

elucidating how the turbulence spectrum evolves Duke University

and the validity of the traditional statistical models Dept of Physics $124,528

of turbulence. We are also studying the mixing Durham, NC 27706 01-C

properties of the turbulence, using temperature as 93 3

a passive scalar. Our preliminary results show a Experimental and Analytical Investigations

clear evolution in the turbulence spectrum as RAis of Flows in Porous Media

increased with the scaling region first occurring R. Behringer, G. Johnson, J. Georgiadis

with a slope of approximately -1.3 (at R - 100)

and then increasing to -1.6 by R, - 200. The

slope does not appear to reach the Kolmogorov Research Objectives: The objectives of this project

value of -5/3 even for our highest R, (of 450). include the characterization, both theoretical and

experimental of fluid flows through porous media.

The particular focus is on fluid convective flow in

porous media. Convection in porous media

occurs, for instance, when a layer of

fluid-saturated porous media is heated from below.

Engineering Research 13 1995
The characterization of porous convections Georgia Institute of Technology

includes both pure fluids and mixtures of different Computational Mechanics Center $61,325

fluids. Long term benefits will be an improvement Atlanta GA 30332 01-A

in the theortical and practical applications of flow 94-3

in porous media in the presence of temperature An Analytical-Numerical Alternating Method

gradients. Relevant practical situations include for 3-D Inelastic Fracture and Integrity

petroleum and hydrology problems where heating Analysis of Pressure-Vessels and Piping at

occurs. Elevated Temperatures

S. Atluri

Scientific Approach: The primary approach is

experimental, and involves the use of Magnetic Current and future power generation plants require

Resonance Imaging (MRI) as a powerful new tool efficient operation so that energy savings may be

to see the flow inside of porous media. The realized. In addition, power generation equipment

project involves the use of a MRI apparatus and a in the US continues to age, creating operational

precision thermal apparatus for carrying out the dangers for the working staff as well as greater

convection experiments. Additional theoretical potential for power outages. Current methods to

work now includes an analysis of the convective ensure safe operation of these plant components

model equations with the goal of understanding which operate in the nonlinear material regime are

recent experimental results. These results show simplistic, and hence, not very reliable. This

a strong coupling between the solid structure of program is developing advanced analytical tools

porous media and the flow states. which can be used to reliably assure safety of

future plants as well as aging plants. Current Status of Project: Recent work has been

described in Shattuck et al. Phys. Rev. 75, 1934 The finite element alternating method is the state-

(1995). These experiments show the strong of-the-art methodology for determining stress

coupling between pore space structure and flow intensity factors for two and three dimensional

patterns. An additional longer paper is in progress. crack growth problems. This method has

This work forms the basis of Mark Shattuck's permitted accurate and simple analyses of linear

thesis. Continuing work will focus on experimental fracture problems to be made so that sophisticated

MRI studies of binary mixture convection in porous reliability assessments of operating equipment

media. may be made. This program has extended the

finite element alternating method so that it may

now be used in the nonlinear regime, i.e., the nonFlorida State University linear finite element alternating method. With this

Supercomputer Computations $100,000 new methodology, sophisticated damage and

Research Institute fracture assessments can be made for

Tallahassee, FL 95-5 components which experience failures in the

elastic-plastic and high temperature creep regime.

Theoretical and Computational Studies of This is truly a revolutionary advance to the fracture

Pattern Formation assessment field.

J. Vinals

Currently, sophisticated fracture assessments are

being made using advanced fracture theories such

No summary information as the T*-integral which were previously

unattainable. The methods are being verified by

comparison of predictions to experimental results.

It is anticipated that these advances will permit the

designer to make sophisticated fracture

assessments in the future with a minimum of

effort.

Engineering Research 14 1995
Idaho National Engineering Lab implemented by combining the tools of intelligent

Applied Physics & Optics Unit $436,000 control including fuzzy logic, expert systems, and

Idaho Falls, ID 83415 06-A neural networks. The ability of a mixed microbial

93-3 culture to adapt to changing conditions will be

Fundamentals of Thermal Plasma Processing matched by the ability of the control system to

J. Fincke learn about process performance continuously. Sensors will be developed to inform the control

The objective of this project is to improve the system about the activity of the dominant strains of

thermal plasma spray process and the microorganisms in the mixed culture. This will be

understanding of high-velocity, high-temperature, combined with expert knowledge on the

nonequilibrium plasma processes. High plasma metabolism and biochemistry of these strains

velocities lead to large departures from chemical incorporated as fuzzy logic rules in the controller.

equilibrium as well as high particle velocities.

Higher particle velocities decrease particle These control concepts are being demonstrated in

residence time, minimize oxidation reactions and the laboratory using the oxidation of ferrous iron

produce denser coatings. Ion and dissociated by Thiobacillus ferrooxidans as a model system. A

species populations are typically larger than controller is being developed first for a pure culture

expected at the local kinetic temperature. Since of this organism in a chemostat, the control

surface recombination increases plasma/particle objective being to maximize the oxidation rate

heat transfer rates producing fully molten particles without the appearance of ferric iron precipitates.

with less residence time. The desired result is to Currently the controller adjusts the temperature,

deliver to the substrate a particle ensemble at pH, and dilution rate adaptively, to find the best

higher velocities with less variance in temperature, set points. Later the culture complexity will be

velocity, molten fraction, and chemical progressively increased by adding an acidophilic

composition. Ultimately this will allow heterotrophic bacterium that consumes organic

improvements in coating adhesion and strength matter known to inhibit Thiobacillus, and a

while other characteristics, such a porosity, can be protozoa that feeds on the bacteria. Appropriate

specified and controlled. This leads to the control rules will be developed and implemented at

possibility of engineering new coatings with graded each step.

composition, porosity, etc.

Diagnostic techniques include coherent Thomson Idaho National Engineering Lab

scattering, Coherent-Anti-Stokes-Raman Spectro- Energy Res & Applications Dept $210,000

scopy (CARS), Laser Induced Fluorescence (LIF), Idaho Falls, ID 83415 06-A

two-photon LIF, degenerate-four-wave-mixing, 93-3

plasma velocity by direct measurement of Doppler Modeling of Thermal Plasma Processes

shifted laser scattered light, particle size, velocity, J. Ramshaw, C. Chang

and temperature, and an enthalpy-probe, mass

spectrometer combination. Optimization of thermal plasma processing

techniques requires a better understanding of the

space- and time-resolved fluid flow and

Idaho National Engineering Lab temperature distribution in the plasma, and of

interactions between the plasma and injected or

Materials Science Division $224,000 condensed particles. The present research is

Idaho Falls, ID 83415 03-A directed toward the development of a

93-3 comprehensive computational model capable of

Application of Intelligent Control Systems providing such information. The plasma is

to Mixed-Culture Bioprocesses represented as a two-temperature multicomponent

J. Johnson, D. Stoner ideal gas governed by the Navier-Stokes

equations. In contrast to much of the earlier work,

The aim of this project is to show that the local thermodynamic equilibrium is not assumed.

productivity of mixed-culture bioprocesses can be Multicomponent diffusion is represented by a

increased by applying intelligent systems to the self-consistent effective binary diffusion

process control problem. Controllers are being approximation, suitably generalized to include

Engineering Research 15 1995
ambipolar diffusion of charged species. The toughness data obtained from standard fracture

further generalization to diffusion in external toughness specimens. Future research will focus

electromagnetic fields is in progress. Dissociation, on predicting the stable crack growth process in

ionization, and other chemical reactions are fully base metal and the fracture process in weldments.

coupled to the plasma flow and are treated by a

new general implicit chemistry algorithm. Diffusion bonded specimens are being used to

Extensions of this algorithm to two-temperature simulate weldments. These specimens are used

plasmas and heterogeneous reactions (such as to study the ability of existing models to predict the

particle condensation) are in progress. Discrete fracture process for weldments. Actual weldments

particles interacting with the plasma are are being fabricated and testing/analysis will be

represented by a stochastic particle model which underway soon.

allows for statistical distributions of particle

properties. Applications to date include This project is a collaborative program with MIT.

simulations of plasma spraying in both

conventional and modem high-speed torches, as

well as studies of chemical, thermal, and excitation Idaho National Engineering Lab

nonequilibrium in thermal plasmas. Future Materials Technology Group $477,000

applications to plasma synthesis are also planned. Idaho Falls, ID 83415 03-A

93-3

Intelligent Control of Thermal Processes

Idaho National Engineering Lab H. Smartt, J. Johnson

Materials Technology Group $687,000

Idaho Falls, ID 83415-2218 01-A This project addresses intelligent control of thermal

93-3 processes as applied to gas metal arc welding.

Elastic-Plastic Fracture Analysis Emphasis Intelligent control is defined as the combined

on Surface Flaws application of process modeling, sensing, artificial

W. Reuter, J. Epstein, W. Lloyd intelligence, and control theory to process control.

The intent of intelligent control is to produce a

The objective is to improve design and analytical good product without relying on post-process

techniques for predicting the integrity of flawed inspection and statistical quality control

structural components. The research is primarily procedures, by integrating knowledge of process

experimental, with analytical evaluations guiding engineering practice and process physics into

the direction of experimental testing. Tests are sensing and control algorithms. The gas metal arc

being conducted on materials ranging from linear welding process is used as a model system;

elastic to fully plastic. The latter extends beyond considerable fundamental information on the

the range of a J-controlled field. Specimens process has been developed at INEL and MIT

containing surface cracks are used to simulate the during the past ten years. Research is being

fracture process (crack growth initiation, subcritical conducted on analytical modeling of nonlinear

growth, and catastrophic failure) that may occur in aspects of molten metal droplet formation and

structural components. transfer, and integration of knowledge-based

control methods (including artificial neural

Metallography and microtopography techniques networks and fuzzy logic based connectionist

have been developed to measure crack tip systems) with iterative learning control methods.

opening displacement and crack tip opening angle Results are being transferred to industrial partners

for comparison with analytical models. Moire through a related ER-LTT/EE-OTT CRADA on

interferometry techniques are used to evaluate and Intelligent Diagnostics, Sensing, and Control of

quantify the deformation in the crack region. Thin Section Welding.

These studies have resulted in the ability to predict

crack growth initiation of specimens containing This project is part of a collaborative research

surface cracks using constraint and fracture program with the Massachusetts Institute of

Technology.

Engineering Research 16 1995
Idaho National Engineering Lab with multiple criteria. The main theme is

Nondestructive Mat'ls Charac Grp $180,000 goal-oriented model simplification for control and

Idaho Falls, ID 83415-2209 03-B decision making. The overall goal is the

93-3 development of new and effective methodologies

Nondestructive Evaluation of for robust control, stabilization and optimization of

Superconductors large scale systems in the presence of static as

K. Telschow well as dynamic uncertainty, and the analysis of

such systems using the concepts of multimodeling,

This project is concerned with the development decomposition and aggregation.

and application of new nondestructive evaluation

(NDE) techniques and devices for the One area of current research is the optimal and

characterization of materials, particularly robust control of structurally-changing, large-scale

high-temperature superconducting materials in uncertain systems, where the structural changes

tape form. Microstructural and, particularly, are stochastic and are modeled by a finite-state

superconducting properties, need to be measured Markov jump process, and the additive

non-invasively and spatially in order to aid the uncertainties in the system dynamics and

fabrication process. measurement channels are deterministic and

norm-bounded. Our focus here is on systems

A noncontacting AC induced current measurement where the transition rates from one structure to

technique has been developed that can determine another exhibit a time-scale separation. Another

critical currents on a local scale. This technique topic of study at the present is optimally robust

can be used in conjunction with external applied control of nonlinear systems with parametric and

fields and DC transport currents to determine additive uncertainty, using the robust identification

spatial variations in critical current dissipation. Its schemes recently developed in the scope of this

operation is based on inducing the critical state project.

and full field penetration into the sample directly

under the probe. A new integral equation

approach has been found that can be solved University Of Illinois

iteratively to determine the flux front profile in Dept of Chemical Engineering $145,000

geometries with azimuthal symmetry accounting Urbana, IL 61801 01-C

that accounts for demagnetization effects. This 95-3

approach has been applied to configurations Gas-Liquid Flow in Pipelines

involving samples in a uniform field and tapes in T. Hanratty

the field of an external coil. The capability of high

temperature SQUID sensors for measurements in The long range goal of this research is to describe

long length tapes is being investigated for induced, the macroscopic behavior of gas-liquid flows by

leakage and trapped fields. developing a phenomenological understanding of

small scale interphase interactions. The simplified

systems of fully-developed flow in vertical and

University Of Illinois horizontal pipes are being used. Studies are

Coordinated Science Laboratory $128,270 being carried out of drop sizes in vertical flows, of

Urbana, IL 61801 03-A asymmetries in horizontal annular flows, of the

94-3 behavior of slugs in slug flow and of the role of

Model Building, Control and Optimization of waves in enhancing transport in stratified gasLarge Scale Systems liquid flows.

T. Basar

Studies of droplet deposition in vertical annular

This program involves fundamental research on flows have revealed the surprising result that

the modeling, control, and optimization of large deposition rates are independent of droplet

scale systems. It encompasses both linear and concentration at large enough concentrations.

nonlinear models, deterministic and stochastic Dropsize measurements suggest that this is

systems with external and internal uncertainty, associated with a transition whereby droplet

systems with weak spatial and weak or strong turbulence is hindered by droplet-droplet

informational links, and dynamic decision models interactions.

Engineering Research 17 1995
Measurements of the liquid shedding rates of volume fraction of martensite is solely dependent

slugs in a gas-liquid horizontal flow have been on the effective stress, and the flow rule is chosen

made. Slug stability may be viewed as a situation such that the ratio of transformation strain

in which the rate of liquid accumulation is equal or components remain constant during deformation.

greater than the rate of shedding. This notion is Our experimental results indicate that there is a

used to improve predictions of the initiation of slug dependence of the transformations strain on the

flow. hydrostatic stress component and the flow rule

assumed in the literature for the transformation is

also incorrect. In view of these experimental

University Of Illinois findings, new transformation models are being

Dept of Mechanical and $67,419 developed.

Industrial Engineering 01-A

Urbana, IL 61801 93-3 Currently, the research continues to focus on

deformation studies under pressure loadings on

Stress Induced Phase Transformations the carburized steels and on the NiTi alloy. The

H. Sehitoglu influence of hydrostatic pressure on the threshold

stress for transformation, transformation kinetics,

The stress-strain behavior associated with and shifts in the transition (martensite start/finish)

austenite -- martensite phase transformation of temperatures for transformation are being

carburized steels and nickel-titanium alloys is quantified with experiments at several

studied. Due to a lack of fundamental temperatures.

understanding of the role of stress on

transformations in pressure type loadings,

advances in these materials and science based- Johns Hopkins University

design with these materials have not occurred. Mechanical Engineering Dept $ 0

Volumetric transformation strains have been Baltimore, MD 21218 01-C

measured on 43110 type steels austenitized at 92-3

950°C and at 843°C respectively with an initial Numerical and Physical Modeling of Twoaustenite volume fraction of 35%. The Phase Flow Phenomena at Large Reynolds

experimental results indicate that the phase Numbers

transformation strains exhibit considerable A. Prosperetti

sensitivity to the hydrostatic stress with phase

transformations occurring under zero hydrostatic The ultimate purpose of this study is to develop

stress case and the limit of transformation strains accurate averaged-equations models of disperse

when the fracture of the specimen was delayed multi-phase flows of engineering significance.

under superimposed pressure. Analytical means are used to derive the form of

the equations and direct numerical simulations to

A number of experiments have been conducted on effect their closure at finite volume fractions.

the NiTi alloys that are known to undergo thermoelastic phase transformations. Unlike steels which A new method of phase averaging has been

exhibit virtually no recoverable transformation developed and applied to rigid and compressible

strains, the transformation strains in this class of spheres in potential flow and in Stokes flow.

materials are partially recovered upon unloading; Analytical results have been obtained in the dilute

depending on the applied strain levels. At low limit and numerical ones for finite volume fractions.

strain rates the transformation occurs through The method is quite flexible and general and has

phase boundary motion while at high strain rates, also been applied to the derivation of averaged

the phase boundary motion was not observed at energy equations at small Peclet number and of

the macroscale. The stress-strain behavior is the particle stress tensor in potential flow. It has

shown to exhibit considerable sensitivity to also been shown that it reproduces - often with

hydrostatic stress under pressure loadings. considerably less effort and greater generality -

many results in the literature.

Constitutive models proposed in the literature for

deformation were evaluated in light of these Current efforts center on the simulation of

results. The current models predict that the suspensions of non-spherical particles in the

Engineering Research 18 1995
potential- and Stokes-flow limits. Approximate properties of coupled wave systems, including

closure techniques at finite concentrations are also elastic waves in solids, electromagnetic waves in

being developed. optical media or plasmas, nuclear wave functions

in molecular physics, and many others; (2) The

development of a new method for decoupling

Robert H. Kraichnan, Inc. coupled wave systems, including systematic

369 Montezuma 108 $67,685 adiabatic perturbation schemes for this purpose;

Santa Fe, NM 87501-2626 01-C (3) The development of asymptotic quantization -933 methods for coupled wave systems, i.e., the

Turbulence Theory determination of normal mode frequencies and

R. Kraichnan eigenfunctions; (4) Investigation of differential

geometric and topological concepts such as

Turbulent flow is omnipresent in geophysics and Berry's phase, gauge structures, and topological

energy-producing devices. Atmospheric turbulent singularities (such as monopole strings) which

transport plays an essential role in the movement generically occur in coupled wave systems; (5) A

of heat, moisture, and pollutants. Turbulent flows systematic study of mode conversion (otherwise

represent an enormous amount of data. Both for called Landau-Zener transitions), in which we

practicable computation and for physical apply bifurcation and catastrophe theory to

understanding, it is necessary to extract the categorize the basic types of mode conversion

essential information in compact form. This project which can occur; (6) Investigations into coherence

explores novel approaches to economical and and radiometry in optics; (7) The development of

meaningful description and computation of theories of mode conversion applicable when

turbulence. During the past two years of this nonlinear effects are important; and (8) A study of

project, explicit statistics have been deduced the non-Abelian gauge fields which occur in the

theoretically for the spottiness of small scales of a separation of rotational and internal coordinates in

contaminant carried by turbulence. This is the first the n-body problem (with applications to celestial

such success for a turbulence problem, and has mechanics, satellite control, and atomic, molecular,

sparked an international follow-up effort. The work and nuclear physics).

has now been tested numerically, by simulations

of unprecedented resolution. A result of this

project should be improvement of schemes for Lawrence Livermore National

economical computation of contaminant dispersal. Laboratory

Dept of Physics $200,000

University of California 06-A

Lawrence Berkeley Laboratory Livermore, CA 94720 94-1

Dept of Physics $249,000

University of California 06-C Steady State and Transient Nucleation

Berkeley, CA 94720 93-3 Kinetics

G. Wilemski

Studies in Nonlinear Dynamics

A. Kaufman, R. Littlejohn This research addresses several fundamental

issues in homogeneous nucleation theory. The

Our research concerns the development of appealing simplicity and wide applicability of

methods of modem nonlinear dynamics with classical nucleation theory is offset by its

applications to problems in physical and inaccurate predictions of nucleation rates. New

engineering sciences. We have been especially molecular theories of nucleation appear capable of

involved with Hamiltonian dynamical systems and providing greatly improved predictions, but

the application of differential geometric and practical application of these theories is currently

topological methods. A main area of application is restricted to the simple rare gas systems. One

wave systems, in which we have taken a broad, aim of this work is to bridge this gap by developing

interdisciplinary perspective. Our interests have theoretical expressions for cluster evaporation

included the propagation, spectra, mode rates based on computer studies of the energetics

conversion, and tunnelling of waves. Major and dynamics of small clusters of more complex

divisions of the program are: (1) A study of the molecules such as water and methanol. To

Engineering Research 19 1995
preserve a modicum of simplicity in the theory, this have now been studied. Because NMR imaging

work will strive to obtain results that depend on is a fairly slow method, it is very important to

only a few readily determined molecular extend the NMR method to faster flows. As a

parameters. point of reference, velocity images have been

made in tens of minutes whereas the achievement

Theoretical work will also be performed to test and of similar results in fractions of seconds will be a

improve various aspects of binary nucleation specific objective for the next few years.

theory. Accurate numerical solutions of the

birth-death equations will be obtained to simulate

binary nucleation kinetics for fluid systems with University Of Maryland

strong compositional surface enrichment, partial Dept of Mechanical Engineering $65,524

miscibility, and significant vapor phase nonideality. College Park, MD 20742 01-D

These results will be used to assess the accuracy 93-3

and applicability of various approximate analytical Characterization of Metal Cutting Dynamics

expressions for the rate of binary nucleation. B. Berger I Minis

Attention will be given to the effects of transient

behavior on binary nucleation rates and to cases The development of energy efficient machine tools

of ridge crossing, i.e., when the major nucleation which produce parts of high quality and require

flux bypasses the saddle point. To improve minimum intervention requires the capacity to

understanding of the effects of partial miscibility on identify precursors of unstable, chatter states and

nucleation, molecular dynamics and Monte Carlo integrate such identifiers into control system

simulations of binary rare gas clusters will be algorithms. Large amplitude oscillations

made to investigate how the internal molecular associated with chatter adversely affect surface

distribution of the two species varies as the finish dimensional accuracy and tool wear often

different interaction strengths are varied. resulting in tool breakage.

This research effort has addressed the

The Lovelace Institutes fundamental issues involved in the identification

Institute for Basic and Applied $55,487 and control of chatter through: (i) creation of a

Medical Research 03-B data base of over 200 cutting experiments

Albuquerque, NM 87108 93-3 comprising 16.107 separate measurements for

ranges of values of depth of cut, turning speed

Two-Phase Flow Measurements by NMR and feed rate; (ii) analysis of time series in the

E. Fukushima, S. Altobelli, A. Caprihan data base with a variety of techniques including

false nearest neighbors, mutual information,

The objective of this grant is to apply NMR to singular value decomposition, time-frequency

study how mixtures of different phases flow. The calculation and polyspectral methods; (iii)

concentration profile of one or both of the phases identification in the data analysis of three nonundergoing flow as well as velocity profile and dimensional measures of the cutting state which

other more esoteric quantities such as acceleration are sufficiently robust for use in the on line control

and diffusion can be measured without interfering of the cutting machine; (iv) incorporation of the

with the flow. The non-invasive measurement of measures of the cutting state into the control

such parameters is especially difficult for system of an existing lathe.

concentrated mixtures that are opaque to the

standard measurement medium such as light and A relationship has been established between the

sound waves but NMR works very well provided cutting state and the structure of the power

we examine proton containing liquids, e.g., water spectra of the time series and its envelope. This

and oil, in nonmetallic containers. research has resulted in the development of

means for the elimination of chatter in orthogonal

Steady flows of concentrated suspensions in a cutting.

circular pipe, first with a constant cross-section

and then with a step expansion and contraction,

Engineering Research 20 1995
University Of Maryland yield considerable physical insight into the

Dept of Electrical Engineering $95,000 behavior of these systems. We have

College Park, MD 20742 06-C benchmarked these codes carefully, and we have

92-3 demonstrated that they yield the same results as

Mathematical Models of Hysteresis computer codes that use far shorter step sizes and

1. Mayergoyz are far less efficient. In addition to Monte Carlo

methods, we are now using analytical methods

This research is concerned with the development based on the theory of stochastic differential

of mathematical models of hysteresis. These equations to completely characterize the

models are phenomenological in nature and, for probability distribution functions forthe evolution of

this reason, they can be applied to the description the signal's state of polarization and the

of hysteresis regardless of its physical origin. corresponding terms in the modified Manakov

equation that describes the complete evolution.

The main research objectives of the ongoing

research can be briefly summarized as follows: The second project is quasi-phase-matched

further development of scalar and vector Preisach waveguides. We are using a Green's function

type models of hysteresis (superposition models, approach to determine the rate at which radiation

two-input models for magnetostrictive and leaks from the quasi-phase-matched guides. In

piezoelectric hysteresis and their tensor the future we will look at oblique guides and

extensions, feedback Preisach-type models), guides with other unusual cross-sections that

development of Preisach-type models for viscosity appear in the experiments to reduce unwanted

(aftereffect), application of Preisach-type models to Bragg reflections.

the description of superconducting hysteresis and

evaluation of hysteretic losses in hard

superconductors, software implementation of the University Of Maryland

Preisach hysteresis models, extensive Dept of Mechanical Engineering $129,319

experimental testing and verification of hysteresis College Park, MD 20742 01-C

models, investigation of penetration of 94-3

electromagnetic fields into nonlinear hysteretic Contaminant Dispersal in Bounded

media. It is hoped that, as a result of this Turbulent Shear Flows

research, the Preisach-type models of hysteresis J. Wallace, P. Bernard, L. Ong

will emerge as a useful and indispensable tool in

engineering research and design problems. Closely coordinated direct numerical simulations

and windtunnel experiments of evolving

line-source plumes are being conducted to better

University Of Maryland understand the physics of the scalar transport and

Electrical Engineering Department $ 0 to develop a methodology for the accurate

Baltimore, MD 21228 03-B prediction of scalar fields in highly sheared

92-3 environments. The latter includes a new class of

Pulse Propagation in Inhomogeneous models which more accurately mimic the

Optical Waveguides dynamical processes affecting plume development.

C. Menyuk Of particular interest is the wall-normal diffusion of

the scalar and its connection to vortical structures

We are presently working on two principal in the wall region, and the efficacy of the transport

projects. First, we are studying randomly varying models in both canonical boundary layer flows as

birefringence in optical fibers and its impact on well as in complex flow geometries with significant

both soliton and NRZ communications. We have flow separation.

derived a set of equations (modified Manakov

equations) that allow us to simulate the A quasi-three-dimensional laser light-sheet

propagation through a fiber with rapidly and tomographic method to visualize the scalar

randomly varying birefringence on the much longer topography of boundary layer plumes has been

length scale on which the signals varying due to implemented. A smoke plume seeped into the

chromatic dispersion, polarization mode flow from a wall slot in the windtunnel (idealizing

dispersion, and nonlinearity. These equations also the dispersion of a passive scalar pollutant

Engineering Research 21 1995
released from a line source in the atmospheric capture the average of the process. The model

surface layer) has been filmed at 10 KHz and has been used, among other things, to

rendered into a 3-D computer movie of constant quantitatively explain the effectiveness of current

concentration surfaces. These images with pulsing for improving drop detachment.

simultaneous measurements of the velocity and

vorticity vectors with a miniature 12-sensor

hot-wire probe provide a database for model Massachusetts Institute Of

development and verification. Technology

The Energy Laboratory $111,100

Massachusetts Institute Of Cambridge, MA 02139 03-A 94-3

Technology Synthesis and Optimization of

The Energy Laboratory $123,688 Chemical Processes

Cambridge, MA 02139 03-B L. Evans, P. Barton

94-3

Metal Transfer in Gas Metal Arc Welding The goal of this research program is to develop

T. Eagar, J. Lang new systematic methods for the synthesis and

optimization of chemical processes. As the

The objective of this project is to find new control chemical industry is one of the largest consumers

methods to improve metal transfer in gas metal of energy in the U.S., it is important to find efficient

arc welding -- a widely-used manufacturing and creative computer-aided design strategies for

process. The goal is to develop a faster process developing new manufacturing processes, and

that is stable. To gain insight on the complex retrofitting existing plants

process, a lumped-parameter mathematical model

of drop detachment from a melting gas metal arc The general philosophy of this research is to

welding electrode has been developed and its develop, in an university environment, innovative

performance compared to an extensive range of generic methodologies for solving problems of

experimental results. industrial importance. These methods are then

demonstrated by using prototype software to solve

A highly-instrumented gas metal arc welding problems typical of those encountered in industry.

experiment which modifies the fundamental way

metal is transferred in the new welding process Research is currently considering three topics. A

has been designed and constructed. The long term program that focuses on synthesis

experiment uses mechanical energy as a new techniques for achieving increased energy

control input to the welding process. The metal efficiency through better heat and work integration

electrode is vibrated axially while welding at the has culminated with an investigation of the

desired frequency of drop detachment in order to simultaneous synthesis and optimization of a

force the detachment of metal drops. The chemical process, its heat exchange network, and

experiment has been used to study vibrated the utility system. Case studies involving an

electrode metal transfer, short duty-cycle current atmospheric crude tower and the cold end of an

pulsing metal transfer, and constant current metal ethylene plant demonstrate that the new approach

transfer with steel and aluminum electrodes. Very can be used to derive designs very close to those

clear high-speed video images of the electrode of mature process technologies, thus enabling new

area provided measurements of the surface process designs to start high on the learning

tension of the molten steel, the oscillations of curve. Secondly, a new initiative is addressing the

drops attached to the electrode, and the dynamics need for process design and optimization

of the drop detachment process. technologies forbatch/semi-continuous processes.

Research is focusing on design tools for rapid and

Experiments show that the electrode model efficient pro- cess development. A prototype

captures the instantaneous geometry and process development methodology has been

dynamics of drop detachment. Hitherto, dynamic proposed that exploits modeling technology to

electrode melting models have only sought to explore alternatives and ensure feasibility of the

Engineering Research 22 1995
design. Finally, a new initiative is investigating Massachusetts Institute Of

improve- ments, such as use of hybrid numerical Tehnolo

and symbolic strategies, to the robustness and ecnoogy

efficiency of numerical algorithms for process National Magnet Laboratory $88,555

simulation and optimization. Cambridge, MA 02139 01-D

93-2

Cryotribology (Low Temperature Friction and

Massachusetts Institute Of Wear): Development of Cryotribological Theories and Application to Cryogenic

Technology Devices

The Energy Laboratory $152,609 Y. Iwasa

Cambridge, MA 02139 03-B

94-3 To advance our understanding of cryogenicMultivariable Control Of The Gas-Metal Arc temperature sliding stability, and thereby to

Welding Process improve the reliability of superconducting magnets,

D. Hardt we have been examining, experimentally and

theoretically, the fundamental mechanisms of

The goal of this work is to provide a well-controlled frictional stability. The attainment of absolutely

welding process, based on multivariable regulation stable, positive friction-velocity characteristics at

of several welding attributes. However, previous cryogenic temperatures appears improbable

work encountered several problems that precluded because of the lack of thermally-activated steadygood regulation of the process -- primary among state shear creep. We are presently investigating:

these was the lack of sufficient controllability of the 1) a force-based approach to magnet design that

process. promotes quench-causing conductor microslips to

occur early in the magnet's charging cycle where

We are taking three approaches to this problem. their consequences are relatively benign; and 2)

The first involves development of a more the cryotribological behaviors at 77K and 4.2 K of

controllable conventional welding process by several metal/metal and other nonpolymeric sliding

creating a plasma process that allows independent pairs, particularly of several hard, creep-resistant,

control of heat and mass transfer to the weld. In chemically inert materials such as: the Group 8

addition, a miniature arc-furnace-based droplet noble metals, high-strength ceramics and recentlyproducing method has been developed that can developed sputter-deposited diamond films. Of

control the heat and mass transfer very precisely, particular interest is the extent to which hardness,

but needs an additional heat source for weldment ductility, and chemical compatibility influence

pre-heating. The third supports the other two by cryogenic-temperature sliding behavior.

investigating applied control theory in the area of

distributed parameter control.

Massachusetts Institute Of

The distributed-parameter work has concentrated Technology

on formulation of a general heat conduction

problem with boundary heating to allow feedback The Energy Laboratory $191,628

control of the temperature distribution in time and Cambridge, MA 02139 01-A

space. Test cases involving both welding and 94 -3

general thermal control in steel processing are Modeling and Analysis of Surface Cracks

being considered. The plasma process and arc- D. Parks, F. McClintock

furnace approaches are being pursued analytically,

with fluid thermal modeling combined with control A methodology for predicting constraint-sensitive

systems theory, and experimentally. In the case plane strain ductile fracture in engineering

of the arc-furnace approach, an apparatus is under structures is being developed. At low toughness,

development to test the concept of "stream the elastic T-stress and K provide a rigorous and

welding;" for the plasma approach, a torch with straightforwardlycalculabletwo-parameterfracture

feedback-controlled plasma flow is under design. mechanics. At loads giving moderate to large- scale yielding, a modification to the standard

Engineering Research 23 1995
effective crack length formulation accounting for viscosity equation based on lubrication concepts

effects of T-stress on plastic zone size gives was applied to suspensions of non-colloidal

simple and accurate estimates of J, compliance, particles. The equation derived for monodisperse

and crack tip constraint based solely on elastic K suspensions was also shown to apply remarkably

and T calibrations. In fully plastic cracking of low well to bidisperse and polydisperse suspensions.

to moderate strength structural metals, asymptotic The polymodal particle size was either uniformly or

elastic-plastic crack tip fields fail to dominate the log-normally distributed, and the broadest size

strain over microstructural length scales, range was 37-212 microns. The maximum

suggesting the utility of rigid/plastic models. Such packing of these suspensions obtained from

fully plastic cracking is based on limit analysis and viscosity measurements were found to be equal to

a micromechanical model of crack tip opening the dry random packing of the same particles

angle that is sensitive to constraint and an divided by 1.19. This is a new dilatancy factor

effective slip angle at the crack tip. The likely to be associated with lubrication layers

corresponding material constraints are being between the particles. The viscosity equation was

determined from bending and tension tests of both also used to describe the behavior of bidisperse

standard and novel design. suspensions with a very large particle size ratio.

Here, the bidisperse viscosity was simulated using

All of these models have been incorporated into the bimodal model. The viscosity equation again

line-spring finite elements for stationary and matched well with the simulated data. The

growing surface-cracked plates and shells, calculated values of maximum packing fraction

providing simple and extraordinarily accurate were consistent with the experimental values for

analysis and simulation of these important smaller size ratios. This lends further support to

engineering flaws. Finally, through finite element the validity of the bimodal model. The bimodal

simulation, the effects of loading, geometry, and approach was next applied to the high-shear-limit

material strength differences are being viscosity of a polydisperse suspension with a size

systematically evaluated for mismatched welds range from submicron to 40 microns. The

containing cracks near and on the fusion surface. separating particle size that divided the distribution

into a fine and a coarse fraction was found to be

1.5 microns. It was determined so as to give the

Massachusetts Institute Of best fit between the bimodal model and experiTechnology iment. The result for the separating particle size

showed that the fine fraction is indeed colloidal.

Dept of Mechanical Engineering $ 0

Cambridge, MA 02139 01-C

Rheoogica and Fow Characteristics of Massachusetts Institute Of Rheological and Flow Characteristics of

Dense Multiphase Slurries Employing a Technology

Bimodal Model Dept of Chemical Engineering $152, 653

R. Probstein Cambridge, MA 02139 06-A

94-3

This research aims to develop a rational Development of Principles & Methodologies

theoretical and experimental methodology for the of Metabolic Engineering

rheological and flow property prediction of G. Stephanopoulos

dense-phase slurries with particles distributed in

size from submicron to several hundred microns. Metabolic Engineering is an emerging field of

The approach models a polydisperse suspension biotechnology aiming at the directed modification

as inherently bimodal, wherein it is considered to of the metabolic pathways of microorganisms,

be made up of a fine fraction which behaves plants and animals using recombinant DNA

colloidally and imparts to the suspension many of technology. The overall objective is to achieve

its important rheological and flow characteristics, overproduction of fuels, chemicals and materials,

and a coarse fraction which behaves as if it were or biosynthesis of novel products through the

in a pure liquid with the same viscous behavior as amplification of selected biochemical reactions or

the colloidal suspension and raises the apparent the introduction of new biosynthetic pathways in

viscosity through hydrodynamic interactions. To metabolic networks. The experimental techniques

describe the behavior of the coarse fraction, a of metabolic engineering are derived from applied

Engineering Research 24 1995
molecular biology and are well advanced. mixture as one of the fraction of larger particles

However, interactions of metabolic pathways and suspended in a hypothetical suspending

the general principles governing metabolic fluxes continuum with a viscosity identical to the effective

in-vivo are poorly understood. The goal of this viscosity of a suspension of the fraction of smaller

research is to contribute to the development of the particles alone. The pressure 'drop' across a ball

tools and principles that elucidate the control of falling through a quiescent suspension, which

flux in metabolic networks. As the problem of constitutes another useful dynamical suspension

determining flux control distributions at the parameter, was measured and, in moderately

individual reaction level is too complex and concentrated suspensions, found to agree well

experimentally intractable, our approach has with theoretical results for the comparable

examined the control of flux exercised by groups pressure drop in a homogeneous Newtonian liquid.

of reactions. Concepts from metabolic control For a ball falling in a highly concentrated

analysis have been extended to groups of suspension, the pressure drop seems to be a

reactions in order to identify the group exercising sensitive measure of phase slip at the containing

the strongest degree of control on the production cylinder walls. Also, spinning-ball rheometry in

flux. The approach is then repeated within the quiescent suspensions has been developed as a

group until single reactions are identified that are useful adjunct to the falling-ball rheometric studies.

of particular importance to the flux of product This technique provides a sensitive measure of

formation. This approach has been applied with phase slip at the spinning ball's surface, as well as

success to the production of aromatic and another experimental benchmark for ongoing

aspartate aminoacids in Corynebacterium and theoretical investigations of slip in disperse

yeasts. systems. Finally, in collaboration with The

Lovelace Institutes, nuclear magnetic resonance

imaging is being used to study flow-induced

Massachusetts Institute Of particle segregation ('hydrodynamic diffusion') in

_Technology' .pipe flow. These data in inhomogeneous flows and

complementary video imaging of individual tracer

Dept of Chemical Engineering $79,862 particles in homogeneous flows will provide much

Cambridge, MA 02139 06-C needed information on the effects of flow on

2 9 5 3 particle interactions and effective rheological

Los Alamos National Lab2 properties at the macroscale.

MEE-9 $200,000

Los Alamos, NM 87545 06-C

91-4 University Of Minnesota

Sandia National Laboratories3 Dept of Mechanical Engineering $127,361

Engineering Sciences Center $200,000 Minneapolis, MN 55455 01-B

Albuquerque, NM 87008-0834 06-C 94-3

91-4 Heat/Mass Transfer Enhancement in

Macrostatistical Hydrodynamics Separated and Vortex Flows

H. Brenner', A. Grahanm, L. Mondy3 R. Goldstein

Experimental, analytical, and numerical studies of The fluid mechanics and thermal transport in

falling-ball 'tracer' particle dynamics in separated and vortex flows are studied to increase

concentrated suspensions composed of dispersed, our knowledge of heat/mass transfer enhancement

neutrally-buoyant spheres and rods comparable in mechanisms.

size to the tracer have been continued and

extended. Falling ball viscometry was shown to be A stepped pin-fin array has been found to be

a useful technique to measure the apparent effective for the enhancement of duct flow

viscosity of mixtures of particles of various shapes heat/mass transfer. Detailed flow and mass

and sizes. When two types of suspended particles transfer measurements to understand the related

(such as spheres and rods) are of disparate sizes, mechanisms have been conducted. A complex

the measured apparent viscosity of the vortex system has been observed near the step

homogeneous mixture could be described region. This step-induced vortex system separates

successfully by a model which approximated the from the step toward the endwall and interacts

Engineering Research 25 1995
with the main horseshoe vortex system, altering Another patent for a non-fouling pressure tap is

the near-wake flow pattern dramatically. It under consideration. It has been found that

produces a remarkable acceleration near the oil-in-water emulsions used as a coal substitute

endwall and a deceleration near the mid-span, fluid and stable water-in-oil emulsions used in the

even suppressing the Karman vortex shedding. processing of synthetic crude oils will lubricate

Enhancement of endwall heat/mass transfer has when flow speed is above a critical one and other

been found in the region with strong flow attainable conditions are satisfied.

acceleration.

Energy separation in vortex flow is being studied University Of Minnesota

with free jets and flow around a cylinder. Energy Dept of Mechanical Engineering $ 0

separation occurring in a free jet, depends on the Minneapolis, MN 55455 06-C

nature of the vortex structure around the jet 92-4

periphery and is greatly affected by acoustic Thermal Plasma Processing of Materials

excitation. An experiment to measure unsteady E. Pfender, J. Heberlein

temperature fluctuations around a cylinder

exposed to high velocity flow is being conducted to The objectives of this program are the

examine the difference between instantaneous and characterization of plasma reactors used for

time-averaged energy separation. A thin film materials processing, in particular for the

resistance temperature sensor, which can deposition of diamond films and the generation of

measure the transient recovery temperature with ultrafine particles. The characterization involves

a frequency of 1000-2000 Hz, is being developed diagnostics and modeling of the plasma - reactant

and a special wind tunnel is being assembled. flow interactions.

One of the reactor configurations characterized is

University Of Minnesota the liquid injection plasma reactor. Droplet

Dept of Aero Eng & Mechanics $108,000 trajectories have been determined with a

Minneapolis, MN 55455 01-C telemicroscope-laser strobe video combination

93-5 giving 100ns exposures of a 50 times magnified

Lubricated Transport of Viscous Materials image. For the highest diamond growth

D. Joseph conditions, precursor droplets appear to impinge

on the substrate surface before completely

The project has as its broad aim the evaporating. A model is being developed for

understanding and technological development of identification of the most important

lubricated pipelines of heavy oils in core annular physico-chemical effects in this process.

flow, and the spontaneous lubrication of oil/water

and water/oil emulsions and for slurry transport. The characterization of rf reactors for ultrafine

The scientific approach relies heavily on powder production has concentrated on calculating

experiments and direct numerical simulations. temperature and velocity profiles for different

Analytically the problem involves the study of reactor configurations and operating conditions to

two-phase flows and deals with migration and provide a basis for optimal reactor design.

segregation of lubricating fluid at the wall. The role

of inertia in centering density matched The establishment of a diagnostic capability based

core-annular flows and in levitating these flows off on laser scattering techniques developed at the

the wall when the fluids have different densities Idaho National Engineering Laboratory has

has been clarified in recent works sponsored produced the first initial results of scattering

under this grant. Experiments on the effects of signals from a plasma jet.

different linings and surfactants on the fouling of

pipe walls with hydrocarbons were carried out. A Further modeling has been concerned with

patent for a "method of preventing fouling of pipe determining accurate transport coefficients for gas

walls for lubricated transport" was obtained for mixtures, because the importance of these data is

cement linings (U.S. Patent No. 5,385,175). increasing for all plasma modeling efforts.

Engineering Research 26 1995
National Academy of Sciences- agreement NASA will provide $2,500,000. The

National Academy of Eng education program will be coordinated with a

research program addressing Solid mechanics and

National Research Council Finite element Modeling, Composite materials,

Washington, DC 20418 $1,249,500 Aerodynamics and impact, as well as Thermal

06-C sciences (Heat transfer and Fluid Dynamics). In

Department of Energy Integrated 95-2 more detail examples of specific projects are

Manufacturing Fellowship Program Improvement of satellite Rendezvous Maneuvers,

T. Rozzell optimization of gear design, analysis of the wear of

diamond tools. Furthermore, these funds will be

Thirty-six three-year predoctoral fellowships in used to strengthen the undergraduate education in

integrated manufacturing are in place administered aeronautics at Southem University.

by the National Research Council, under the aegis

of the National Academy of Engineering, following

national competitions. The objectives of the National Institute Of Standards

program are to create a pool of PhD's trained in T hnl

the integrated approach to manufacturing, to Technology

promote academic interest in the field, and to Thermophysics Division $ 0

attract talented professionals to this challenging Boulder, CO 80303 06-A

area of engineering. Gelation of Dense Silica Suspensions:

The fellowship program was conceived as one Effect of Shear

response to the loss of competitiveness of the H.J.M. Hanley

United States in manufacturing. Two related

aspects of the problem are the traditional The project examines the gel structure of silica by

separation of the product design function from the SANS (smal angle neutron scattering) and light

manufacturing function and the lack of an scattering measurements. The goal is to extend

appreciation for the process of manufacturing as the current understanding of how gels form on a

an integrated system. microscopic scale, and to determine what specific changes are induced in the microscopic structure

It is expected that the improved manufacturing by the influence of an applied shear. Scattered

methods which this fellowship aims to bring about intensity data were taken on the 30 m SANS

will contribute to improved energy efficiency, to instruments at the NIST Cold Neutron Research

better utilization of scarce resources, and to less Facility. Samples were aqueous suspensions of

degradation of the environment. Ludox silica particles of nominal diameter 24 nm.

Gelation was induced by adjusting the pH and salt

content of the suspensions. The series of

Natinonal Aeronautircs and experiments were repeated with the silica samples National Aeronautics and loaded into the NIST Couette shearing cell. The

Space Adminstration results showed that shear most conclusively

600 Independence Avenue, S.W. $107,630 influences the structure of the gel. On the

Washington, DC 20546 06-C assumption that an investigation of the

94-5 decomposition of a system to a solid would lead to

Center for Aerospace Research & Education an insight into the gelation mechanism, a

for Minority Students at Southern University simulation of a two dimensional Lennard-Jones

I. Blankson system was initiated. A striking similarity between

the computer results and the SANS data was

Pursuant to an agreement between the Secretary observed. A scaling relation for the time evolution

of Energy and the Administrator of NASA, the of the structure factor of a decomposing system

recommended funds will support the education of has been proposed. The relation will lead to a

minority students at Southern University (an novel procedure to analyze scattering from dense

HBCU) in disciplines related to aeronautics and gels.

space sciences. Over the five years of this

Engineering Research 27 1995
National Institute Of Standards emphasis of the research is to investigate HTS-

& Technology semiconductor contact systems and novel HTS- semiconductor devices. The ultimate goal is to

Thermophysics Division $416,000 develop HTS thin-film technology to its fullest

Gaithersburg, MD 20899 03-B potential for multimodule interconnections, future

Boulder, CO 80303 91-5 ULSI source and drain connections, and

microelectronic microwave filters. These potential Development of Measurement Capabilities for applications provide the motivation for a thorough

the Thermophysical Properties of Energy- investigation of HTS thin-film materials

Related Fluids development of these hybrid systems.

R. Kayser, J. Levelt Sengers, M. Moldover, Determining the compatibility of HTS thin-film

W. Haynes deposition and patterning processing with that of

standard Si and GaAs processing is crucial for

The major objectives of this project are to develop expanding the applications of these hybrid

state-of-the-art experimental apparatus for technologies.

measuring the thermophysical properties of a wide

range of fluids and fluid mixtures important to the The nanostuctural properties of HTS materials

energy, chemical, and energy-related industries have proven to have a principal influence on the

and to carry out carefully selected benchmark electrical properties of HTS materials and devices.

measurements on alternative refrigerants and For this reason the use of scanned probe

refrigerant mixtures. The specific measurement microscopies are being emphasized for evaluating

capabilities completed or under development HTS-semiconductor epitaxy as well as electrical

include new apparatus for transport properties conduction in interconnects and contacts to hybrid

(tantalum-hot-wire thermal-conductivity apparatus, device structures. The further development of

vibrating-wire viscometer), thermodynamic scanned probe microscopies, specifically for

properties (dual-sinker densimeter, high- electronic device imaging will be invaluable not

temperature vibrating-tube densimeter, total- only for the HTS-semiconductor integration studies

enthalpy flow calorimeter), phase equilibria but for all developments in microelectronics in the

properties (recirculating phase equilibria foreseeable future.

apparatus, low and high-pressure ebulliometers,

re-entrant radio-frequency resonator), and

dielectric properties (concentric-cylinder dielectric- The City University Of New York

constant apparatus). These new apparatus extend

significantly the state of the art for properties The City College $133,639

measurements and make it possible to study a The Benjamin Levich Institute 06-C

wide range of complex fluid systems (e.g., highly for Physico-Chemical Hydrodynamics 95-4

polar, electrically conducting, and reactive fluids) New York, NY 10031

under conditions which have been previously

inaccessible. inaccessible. The Rheology of Concentrated Suspensions A. Acrivos

National Institute Of Standards This research program aims to investigate the flow

of concentrated suspensions of non-colloidal

& Technology particles from the fundamental point of view.

Electromagnetic Technology Div $86,000 Earlier studies by the Principal Investigator and his

Boulder, CO 80303 06-C associates have shown that the rheology of such

94-3 systems is strongly affected by the shear-induced

High-T. Superconductor-Semiconductor migration of particles from regions of high shear to

Integration and Contact Technology low and from regions of high particle

J. Moreland, S. Russek, S. Sanders, J. Ekin concentrations to low which, by distorting the

particle concentration profile, can lead to an

The purpose of this project is to study materials erroneous interpretation of the experimental

problems faced in integrating high-Tc measurements pertaining to the effective viscosity

superconductor (HTS) thin-film technology with of such systems. This shear-induced particle

conventional semiconducting technologies. The diffusion is also responsible for the phenomenon

Engineering Research 28 1995
of viscous resuspension whereby, in the presence expected of any exothermic reaction system. Input

of shear flow, a settled bed of heavy particles can multiplicities exist and limit control to regions

resuspend even under conditions of vanishingly where the process gains are nonzero.

small Reynolds numbers.

Major attention this year was given to the choice

A theoretical model of shear-induced particle of decentralized control structures for partial

diffusion, which was developed earlier by the control. Based on the FCC, there are several

Principal Investigator was tested experimentally in results that should be of wide interest: (1) An

various unidirectional flows by measuring the FCC can be stabilized and controlled by a 2x2

extent of viscous resuspension and comparing it to matrix; (2) A control matrix useful in one domain

the theoretical predictions. Very good agreement of operation may not be in a different domain, (3)

was found between theory and experiments even One must look beyond setpoint tracking

in the case of flow in a tube where strong performance to judge the suitability of a given

secondary flows are generated owing to the matrix; and (4) Linear algorithms are satisfactory

presence of a non-axisymmetric particle for loop tuning but the impact of nonlinearity

concentration profile. In addition, a technique was determines the choice of the primary matrix.

developed, using LDA, for measuring the particle

velocities in concentrated suspensions. This

technique is currently being used to measure The City University Of New York

instantaneous 3-d particle velocities in The City College $110,250

concentrated suspensions undergoing a variety of The Benjamin Levich Institute 06-C

shear flows in order to further test the predictions New York, NY 10031 94-3

of the theoretical model.

Studies in Physico-Chemical Hydrodynamics

of Extended Systems

The City University Of New York G. Sivashinsky

The City College $ 0

Dept of Chemical Engineering 03-A The objective of this project is a unified theoretical

New York, NY 10031 94-3 approach to the description of a variety of physicochemical hydrodynamics systems characterized by

Partial Control of Complex Processing a significant disparity between the spatial scales

Systems involved. By appropriately performed averaging

R. Shinnar, I. Rinard over short scales one may considerably simplify

the original problem, sometimes even lowering its

There are two research objectives. One is to effective dimensionality and thereby making the

understand the control of Fluidized Catalytic latter quite tractable either analytically or

Crackers (FCC's), an important goal in itself. The numerically.

second is to use the FCC as an example to learn

about the control of complex chemical plants in With all their relative simplicity the emerging

which the number of variables to be maintained reduced models proved rich enough to capture

within acceptable limits exceeds the number of many nontrivial features of the original systems

manipulatable variables available for control. which hitherto resisted description by any other

means. Specifically, the scale-separation

The dynamic simulation model of the FCC approach will be applied to (1) the mathematical

developed previously has been published and is modelling of stabilization, blowoff and flashback of

available on request. The study of multiple steady premixed gas flames; (2) the theory of thermal

states and input multiplicities was completed and explosion in the reactive premixture subject to the

accepted for publication. In the region of current effects of natural or forced convection; (3) the

operation and over a wide range of model nonlinear dynamics of the interfacial instabilities in

parameters, FCC's exhibit only the three steady multilayered flows dominated by viscosity effects.

Engineering Research 29 1995
State University Of New York this work. Thin film technology does, however,

Department of Physics $191,012 also include high Tc superconductor films, films for

Stony Brook, NY 06-C magnetic recording, superlattices and films for

95-3 band-gap engineering and quantum devices. The

Sub-Electron Transfer of Electric Charge in studies carried out on this project also have

Semiconductor Nanostructure relevance to those applications.

K.K. Likharev

Both the film and the substrate are generally

The main goal of this project is to carry out a anisotropic. A line-focus acoustic microscope, is

complementary set of experimental and theoretical being used to measure the speed of wave modes

studies of the continuity of electric charge transfer in the thin film/substrate system. This microscope

in semiconductor heterostructures. has unique advantages for measurements in

anisotropic media. Analytical and numerical

The interplay of continuous (sub-single-electron) techniques are employed to extract the desired

and discrete transfer of charge in solid state information on the thin film from the measured

systems is the basis of several new physical data. Recent results include: (1) use of multiple

phenomena predicted and observed since the mid- wave modes to determine thin film constants, (2)

1980s, including the Coulomb blockade, Coulomb measurements of superlattice film constants, and

staircase, single-electron-tunneling (SET) (3) investigation of the effect of surface roughness.

oscillations, Bloch oscillations, etc. These effects

are considered as the possible basis of a novel

generation of future "single-electron" devices, Northwestern University

circuits, and systems. However, to our knowledge, Dept of Chemical Engineering $139,916

the conditions and limitations of the sub-single- Evanston, IL 60208 01-B

electron transfer of charge, especially in the most 95-3

important case of poorly-conducting structures of Theory of Subcooled Boiling

small size, have not been studied. The main S. Bankoff, S. Davis

objective of this work will be a combined

(experimental and theoretical) study of the The objective of this work continues to be the

discreetness of the charge transfer in study of the dynamics, stability and rupture of thin

semiconductor nanostructures, in particular in liquid films, especially with heat and/or mass

conditions of space-confined electron hopping. transfer. These films appear in many engineering

processes, such as film coating, gas absorption,

condensation, and especially cooling of hot

Northwestern University surfaces.

Engineering & Applied Science $91,537

Evanston, IL 60208 03-B In the long-wave linear stability limit, destabilizing

93-3 mechanisms are identified. For arbitrary

Thin-Film Characterization and Flaw wavenumbers, a shear-mode instability exists that

Detection is stable in plane Poiseuille flow. Regions are

J. Achenbach determined in which the primary instability is to

long-wave disturbances. A weakly nonlinear

This work is concerned with the determination of analysis reveals that small-amplitude disturbances

the elastic constants of thin films deposited on are governed by perturbations of the Kuramotosubstrates, with the measurement of residual Sivashinsky equation. Hysteretic transitions are

stresses in such films and with the detection and found between smaller- and larger-amplitude

characterization of defects in thin film substrate traveling wave states. In the strongly nonlinear

configurations. regime, stable solitary traveling-wave solutions are

found when only viscous effects are considered.

There are many present and potential applications A criterion for the flooding phenomenon, derived

of configurations consisting of a thin film deposited from this analysis, compares qualitatively with

on a substrate. Thin films that are deposited to phenomenologically-based models, The stability of

improve the hardness and/or the thermal the solution to three-dimensional disturbances is

properties of surfaces are of principal interest in then investigated. A strongly nonlinear system is

Engineering Research 30 1995
derived that determines the evolution of the scale using both analytical and numerical

interface and the pressure field. A linear analysis methods. Now we will consider how capillary and

of this equation provides conditions for three- surfactants affect the stability and mobility of foam

dimensional instability. A weakly nonlinear flow in a porous media. Also, we will continue a

analysis concludes that amplitudes of two- study on how capillary effects on the microscopic

dimensional traveling waves are governed by a scale affect the motion of an immiscible

two-dimensional complex Ginzburg-Landau contaminating liquid in an unsaturated porous

equation, with the anisotropic nature of the flow material. Finally, we will investigate the dynamics

displayed in the diffusion coefficients. Stability of of a fluid interface during breaking. Breaking

the two-dimensional monochromatic wave is phenomena occur during the dynamics of twoexamined, and possible three-dimensional patterns phase flows.

are discussed.

The experimental program is designed to confirm Northwestern University

the range of validity of the theoretical analysis, and Dept of Chemical Engineering $111,000

to determine its practical limits. An inclined-plate Evanston, IL 60208-3120 06-C

apparatus has been constructed consisting of a 95-3

glass sheet 1 m long and 0.5 m wide, with Fragmentation and Dispersion of Powdered

adjustable inclination and radiant heating. Global Solids in Viscous Liquids

views of the instantaneous wave structure are J. Ottino

obtained by fluorescent illumination and digital

imaging. Spatial development of the wave The objective of this work is to produce basic

structure and the approach to film dryout are thus understanding of dispersion and mixing processes.

obtained. Work under this grant involves two main areas --

Mixing of Viscous Liquids and Mixing of Powders

-- these two areas being bridged by work on

Northwestern University mixing of concentrated suspensions and pastes.

Dept of Eng Sci & App Math $53,762 Work in mixing of liquids involving modelling

Evanston, IL 60208 01-C studies in aggregation, fragmentation and

94-3 dispersion in regular and chaotic flows. Several

Microscopic Interfacial Phenomena During scenarios have been considered: growth with

Flow in Porous Media constant capture radius, compact

M. Miksis volume-preserving clusters, and fractal

aggregates. Numerical simulations show that the

The objective of this work is to study the effect of average cluster size of compact clusters grows

interfacial phenomena on the motion of a fluid in a algebraically, while the average cluster size of

porous material. In particular, we will be primarily fractal clusters grows exponentially; companion

concerned with the micromechanics of the fluid mathematical arguments are used to describe the

motion and its effect on the macroscopic flow. On initial growth of average cluster size and

the pore scale, we find a moving boundary polydispersity. It is found that when the system is

problem for the fluid/fluid and the solid/fluid well mixed and the capture radius independent of

interfaces. During this project period, attention will mass, the polydispersity is constant for long-times

be directed to understanding and modeling the and the cluster size distribution is self-similar.

dynamics of these interfaces. In particular, Furthermore, our simulations indicate that the

attention will focus on three specific topics: fractal nature of the clusters is dependent upon

surfactant effects, motion of an interface into an the mixing. The work in powder mixing involves

unsaturated porous medium and breaking theory and experiments in non-cohesive systems.

phenomena. Theoretical work involves a combination of

geometrically based methods and particle dynamic

We have recently investigated how capillarity calculations focusing primarily on slow mixing by

affects the dynamics of a foam on the microscopic tumbling .

Engineering Research 31 1995
Northwestern University University Of Notre Dame

Dept of Eng Sci & App Math $69,930 Dept of Chemical Engineering $ 0

Evanston, IL 60208 06-C Notre Dame, IN 46556 01-C

95-3 92-3

Stability and Dynamics of Spatio-Temporal Wave Dynamics on Falling Films and Its

Structures Effects on Heat/Mass Transfer

H. Riecke H-C. Chang

The objective of this project is to improve the The funded project is a study of how interfacial

understanding of systems exhibiting waves evolve on a thin falling film and how these

spatio-temporal chaos by investigating waves enhance heat and mass transfer in many

paradigmatic cases. The research encompasses industrially important devices like solar energy

fundamental and applied aspects. Fundamental collectors, desalination evaporators, pollutant

issues to be addressed are the characterization scrubbers, distillation columns, etc. Understanding

and classification of states which are disordered in the various wave transitions, from small-amplitude

space and time. In applications, spatio-temporal sinusoidal waves with linear dynamics to largechaos arises in systems ranging from fluid flow to amplitude solitary waves with highly nonlinear and

lasers and coupled oscillators. For instance, in chaotic dynamics, would also be important in the

wide-area lasers and in laser arrays fields of hydrodynamics and dynamical systems.

spatio-temporal chaos can reduce the quality of

the laser beam and can even be detrimental to the During the 1995 fiscal year, we have completed

device itself. Stabilization and control of the beam the understanding of the wave dynamics. How

requires a detailed understanding of the origin and small-amplitude inlet noise triggers sinusoidal

the nature of the chaotic state. waves, how these waves evolve into solitary

waves and how the solitary waves interact to

Using analytical and numerical techniques, a produce wave texture coarsening downstream

number of paradigmatic systems will be studied: have been deciphered and quantified. The texture

parametrically driven waves of different types with coarsening phenomenon is most important in

special emphasis on the effect of parametric mass/heat transfer enhancement and the latter

driving on unstable laser beams; the stability and subject will be scrutinized next. Our results

chaotic dynamics of traveling waves as found in obtained in FY 1995 are published in the following

convection of liquid crystals; the role of heteroclinic articles and two additional articles to appear:

cycles in chaos in rotating convection.

(1) Cheng, M. and Chang, H.-C., "Competition

Presently, the dynamics of unstable parametrically between subharmonic and sideband secondary

driven waves is studied in 1 and 2 dimensions with instabilities of a falling film", Phys. Fluid, 7, 34-54

focus on the unexpected behavior of defects in the (1995).

wave pattem. Progress towards the

characterization of the chaotic state is made. The (2) Chang, H.-C., Demekhin, E. A. and Kalaidin, E.

stability of oblique combinations of traveling waves N., "Interaction dynamics of solitary waves on a

(traveling rectangles) is studied. falling film", J. Fluid Mech., 294, 123-154 (1995).

Their stability is found to be quite different than

that of single waves. Consequences for

experimental observations are investigated.

Engineering Research 32 1995
Oak Ridge National Laboratory In the area of computational nonlinear science,

Engineering Physics $1,233,000 CESAR pursues the development of fundamental

and Mathematics Division 03-C methods, including neural networks, wavelets,

Oak Ridge, TN 37831 94-3 stochastic approximation, global optimization, and

parallel processing algorithms for solving complex

Center for Engineering Systems Advanced scientific or engineering problems modeled by

Research (CESAR) partial differential equations and/or involving

J. Barhen, E. Oblow, L. Parker, N.S.V. Rao remote sensing components.

The primary mission of CESAR is to develop,

through innovative research, a core of excellence Oak Ridge National Laboratory

in the areas of intelligent and nonlinear systems Bioprocessing Research and $185,000

technology. By combining long-range Development Center 06-A

future-oriented R&D efforts with near-term, Oak Ridge, TN 37831 94-3

sustained technology transfer to U.S. industry and

graduate student education (on-site assignments A Study of the Mechanisms of Liquidfrom universities), CESAR strives to enhance U.S. Emulsion Bioreactor Systems

scientific and technological capabilities in strategic T. Scott

areas vital to energy independence, national

security, and international competitiveness. Biphasic liquid-liquid systems, in which a

biocatalyst is in an aqueous phase and the

Beginning in FY 1995, CESAR's efforts emphasize substrate is primarily in an immiscible organic

two new basic research areas: computational phase, represent an important class of

nonlinear science and cooperating autonomous nonaqueous bioprocessing options. The approach

systems. Research objectives are chosen to at ORNL is to use high-intensity pulsed electric

address the technology-base requirements for fields to disperse aqueous droplets into immiscible

DOE missions that rely on the use of intelligent organic phases in order to provide surface area for

systems, or require the solution of "grand reaction. Results using horseradish peroxidase

challenge" problems, where the development of suggest that the reaction occurs predominantly at

novel algorithms for efficient utilization of high the liquid-liquid interface and that depending on

performance computing technology plays a critical the solvent used enzyme life is enhanced when

role. using a solvent that interacts with the enzyme and

provides alternative pathways to suicide

We characterize intelligent machines as systems deactivation by cofactors. Related studies have

that integrate perception, reasoning, and action to shown that the viability of whole cells cah be

perform tasks under circumstances that either are enhanced or remain unaffected or that cells may

insufficiently known in advance or dynamically be killed by manipulating delivery of pulsed electric

change during task execution. Perception, fields in multiphase liquid systems. Further results

reasoning, and action, as well as the integration of in multiphase systems have shown that pulsed

these modules into working systems, present electric fields may be used to amplify Rayleigh

challenging issues for inter-disciplinary basic instabilities in conducting liquid laminar jets. This

research. We continue to investigate a wide technique allows for high-capacity production of

variety of such issues in the areas of cooperating uniform, millimeter-sized liquid drops from nozzles.

agents, mobility, manipulation, intelligent

multi-sensory systems, empirical estimation and

machine learning.

Engineering Research 33 1995
Pacific Northwest Laboratory University Of Pennsylvania

Battelle Memorial Institute $50,000 Dept of Mech Eng & App Mech $15,999

Richland, WA 99352 01-B Philadelphia, PA 19104 01-C

91-4 95-1

Radiative Transfer Through Arrays of Active Control of Convection

Discrete Surfaces with Fixed Orientation H. Bau

M. Drost

Active, feedback control strategies to alter flow

Radiative heat transfer in an array of discrete patterns in a fluid layer heated from below and

surfaces is an important and poorly understood cooled from above (the Rayleigh-Benard problem)

class of radiative heat transfer problems. The are being studied experimentally and theoretically

objective of this study is to develop an Our objectives are to (i) stabilize the no-motion

understanding of the impact of array geometry, state of Rayleigh-Benard convection (delay to

surface properties, and incident radiation higher values of the Rayleigh number the

characteristics on radiation heat transfer in the transition from the no-motion to the motion state);

array. The results of the study will be used to and (ii) suppress (laminarize) oscillatory and/or

establish criteria for the valid application of chaotic convection. This work is an extension of

participating media models to arrays of fixed our earlier research effort in which it was

discrete surfaces. successfully demonstrated experimentally and

theoretically that feedback control can be used in

The approach consists of using an innovative a thermal convection loop to tame chaos. The

Monte Carlo model to evaluate radiation heat results of our current work may be important to

transfer in arrays of fixed discrete surfaces with a among other things, materials processing and

range of array configurations. The Monte Carlo crystal growth applications in which it is desirable

model will be validated by comparison with to eliminate convective currents or suppress

experimental results being developed at Oregon oscillatory convection. Thus far, it has been

State University. The Monte Carlo simulations will theoretically demonstrated that, with the aid of a

be used as a benchmark for comparisons with feedback controller, the transition from the nodifferent analytical approaches that model the motion to the motion state and the transition from

array as a participating medium. time-independent to time-periodic convection (Hopf

bifurcation) can be significantly delayed. An

FY 1994 accomplishments consist of: 1) Based on apparatus for experimental verification of our

a comparison of the results of a Monte Carlo theoretical predictions is under construction. The

model for radiation impinging on an array of apparatus consists of a cylindrical cavity heated

discrete surface and a Monte Carlo model of a from below and cooled from above. The heating

homogeneous media we have demonstrated that surface consists of an array of individually

arrays of fixed discrete surfaces cannot, in most controlled, thermal actuators micromachined on a

cases, be modelled as a homogeneous medium. silicon substrate. What is learned during this

Most previous investigators have assumed that research may also be useful for devising control

arrays of fixed discrete surfaces can be modeled strategies for other non-linear flow phenomena.

as homogeneous media. 2) Completed a model For instance, a colleague and I have shown

and an evaluation of the impact of polarity on theoretically that control strategies similar to the

Monte Carlo modeling. The results show that ones developed here can be used to delay or

polarity of incident radiation can significantly affect advance the loss of stability of planar Poiseuille

the interaction between the incident radiation and flow.

an array of fixed discrete surfaces. 3) The MCLITE

cell-to-cell transport Monte Carlo code has been

validated against experimental data. 4) One

technical paper was published in FY 94 and three

journal articles were submitted in to journals for

publication in 1994 and two journal articles were

accepted for publication.

Engineering Research 34 1995
Pennsylvania State University investigations. The following major projects were

Mechanical Engineering Dept $94,981 completed during the reporting period.

University Park, PA 16802 01-B

95-y3 PThe scalar and dynamic structure of premixed and

Research on Combustion-Driven HVOF nonpremixed counterflow methane/air, propane/air

Thermal Sprays and hydrogen/air flames has been experimentally

G. Settles investigated by using non-intrusive laser-based

techniques and computationally simulated with

High-velocity oxy-fuel (HVOF) thermal sprays detailed chemistry and transport descriptions.

comprise a promising, relatively-new coating Results show that the scalar structure including

technology combining the fields of materials, the thickness of a freely-propagating or

manufacturing, combustion, and gas dynamics. freely-standing premixed flame is insensitive to

HVOF uses combustion to melt and propel solid strain rate variations such that the flame cannot be

particles at high speeds onto surfaces to be extinguished by strain alone. On the other hand,

coated. The goal of this research is to understand the thickness of a nonpremixed flame scales

and improve the HVOF deposition of inversely with the square root of the strain rate,

corrosion-resistant coatings, which are important in implying that it can be extinguished by straining.

many energy-related industries. Both experiments Experimental studies on the dynamic structure

and modeling are involved. The transfer of demonstrate the need to allow for the effect of

technology from rocket propulsion and supersonics thermophoresis on the motion of the seeding

is also an important element of this research. An particles when using laser Doppler velocimetry in

early discovery was the very rapid mixing of the measuring the flow velocity.

HVOF plume with the surrounding atmosphere. The dynamics and geometry of flame surfaces in

Experiments on HVOF inert-gas shrouding are nonuniform flows have been analytically and

now being conducted to gain knowledge leading to computations studied, including the phenomena of

a practical shroud for use with commercial HVOF stretch, local extinction, cusp formation and

equipment at usual standoff distances for the broadening, and burning rate augmentation

control and minimization of coating oxides. through flame wrinkling.

Further, nozzle design and operating-parameter

variations are being exploited to achieve an

optimum balance of kinetic and thermal energies Princeton University

of HVOF spray particles, thus to produce desirable Dept of Civil Engineering $101,185

coating properties such as high density, low Princeton, NJ 08544 06-A

porosity, and high corrosion resistance. 93-4

Transport Properties of Disordered Porous

Results of the research are presented yearly at the Media From The Microstructure

National Thermal Spray Conference. One Ph.D. S. Torquato

(C. Hackett) has been educated thus far under this

project. This research program is concerned with the

quantitative relationship between transport

properties of a disordered heterogeneous medium

Princeton University that arise in various energy-related problems (e.g.,

Dept of Mech & Aero Eng $90,000 thermal or electrical conductivity, trapping rate,

Princeton, NJ 08544 06-B and the fluid permeability) and its microstructure.

93-3 In particular, we shall focus our attention on

Mechanisms and Enhancements of Flame studying the effect of: porosity, spatial distribution

Stabilization of the phase elements, interfacial surface

C. Law statistics, anisotropy, and size distribution of the

phase elements, on the effective properties of

The program aims to gain fundamental models of both unconsolidated media (e.g., soils

understanding of the structure and stabilization and packed beds of discrete particles) and

mechanisms of premixed and nonpremixed flames consolidated media (e.g., sandstones and sintered

through theoretical and experimental materials).

Engineering Research 35 1995
Both theoretical, computer-simulation, and experimentally but have heretofore eluded

experimental techniques have been employed to prediction. Thesefeaturesincludedouble-diffusive

quantitatively characterize the microstructure and layering in the melt, development of an irregular

compute the transport properties of disordered liquidus front, remelting of solid, development of

media. Statistical-mechanical theory has been flow channels in the mushy region, and the

used to obtain n-point distribution functions and to establishment of characteristic macrosegregation

study percolation phenomena in continuum patterns (regions of significantly different

random-media models. For example, the pore- composition) in the final solid. Theoretical and

size distribution, lineal path function, and the experimental studies have also revealed means by

chord-length distribution function have been which macrosegregation may be actively

investigated and computed. This has led to suppressed, as, for example, through the

accurate predictions of transport properties of application of a magnetic field or intermittent

realistic models of isotropic as well as anisotropic rotation of the mold.

heterogeneous media. Cross property relations

have been derived. Rigorous relations which link

the fluid permeability to length scales obtainable Purdue University

from Nuclear Magnetic Resonance experiments School of Nuclear Engineering $125,000

and the effective electrical conductivity have been West Lafayette, IN 47907 01-C

derived. Moreover, the effective conductivity has 93-3

been related to the effective elastic moduli. Interfacial Area and Interfacial Transfer in

Recently, 3-D images of a sandstone have been Two-Phase Flow

obtained using x-ray tomographic techniques and M. Ishii

statistical corrleation funcations have been

extracted from them. The objective of the research program is to

develop instrumentation methods, experimental

data base and models for describing the interfacial

Purdue University structure and behaviors of two-phase flows. In

School of Mechanical Engineering $103,571 terms of the flow structure, the transverse

West Lafayette, IN 47907 01-C distributions of the local void fraction, interfacial

93-3 area concentration, fluid particle size and their

Effect of Forced and Natural Convection axial development from the entrance to the exit will

on Solidification of Binary Mixtures be the primary focal point of the experimental

F. Incropera research. For the purpose of understanding the

dynamic behaviors, the interfacial velocity, fluid

This study deals with the influence of combined particle coalescence and disintegration are

convection mechanisms on the solidification of studied. The axial changes in the distribution of

binary systems. A major accomplishment of void fraction and interfacial area give the

research performed to date has been the information on the particle coalescence and

development and numerical solution of a disintegration. These are used to quantify the flow

continuum model, which uses a single set of regime transitions. The multi-sensor probes are

equations to predict transport phenomena in the used together with hot-film probes for these

liquid, "mushy" (two-phase), and solid regions of measurements. The focus of the modeling effort

the mixture. Calculations have been performed for is to develop an interfacial area transport equation

aqueous salt solutions and/or lead/tin alloys which incorporates the mechanistic models for

involving forced convection, thermo/solutal natural coalescence and disintegration of fluid particles.

convection, and/or thermo/diffusocapillary This transport equation describes dynamical

convection. The calculations have revealed a change of the interfacial structure and replaces the

wide variety of rich and robust flow conditions, conventional model based on flow regime

including important physical features of the transition criteria.

solidification process which have been observed

Engineering Research 36 1995
Purdue University analysis of high temperature components, forming

School of Mechanical Engineering $119,000 analysis and life prediction.

West Lafayette, IN 47907 01-B

93-3 Modeling of recovery of state and other softening

Near-Wall Measurement of Sublayer effects observed in modified 9Cr - 1Mo Steel at

Dryout and Theoretical Modeling of 5380

C within the context of the viscoplasticity

CHF in Vertical Channels theory based on overstress (VBO) has been

1. Mudawar completed. Analysis of finite deformation

experiments revealed that presently existing

This project targets the development of a plasticity and viscoplasticity theories are limited in

theoretical model for critical heat flux (CHF) from reproducing the observed, texture based

long heated walls in vertical flow. Flow boiling deformation induced anisotropy. Ideas have been

pattern is examined with the aid of developed on how to model the deformation

photomicrographic and high-speed video imaging induced anisotropy for elastic and inelastic

techniques in order to determine the CHF trigger beavior within the context of VBO.

mechanism. Close-up studies of the wall region

have revealed features common to most bulk flow A et of biaxial, low-cycle fatigue tests with

conditions. At fluxes below CHF, the vapor stainless steel tubular specimens at 538°C has

coalesces into a wavy layer which permits wetting been completed. During cycling, changes in the

only in wetting fronts, portions of the liquid-vapor voltage drop were monitored using a reversing

interface which contract the wall as a result of the direct current potential drop measuring system

interfacial waviness. These waves are generated built at RPI. Data analysis included digital filtering

from the heater's upstream region with and tensor spline smoothing. Curves of

wavelengths following predictions based upon the normalized, incremental potential drop vs.

Kelvin-Helmholtz instability criterion. Critical heat circumferential position showed peaks growing in

flux occurs when the pressure force exerted upon time near cracks formed in the specimen.

the interface due to interfacial curvature, which Theoretical electrostatic potential field models for

preserves interfacial contact with the wall prior to a through-slit crack in a finite width plate and for a

CHF, is overcome by the momentum of vapor at semi-elliptical crack in a semi-infinite medium were

the site of the first wetting front, causing the analyzed following the method adopted for the

interface to lift away from the wall. Recent studies experimental data. Comparison of experimental

have shown this interfacial lift-off criterion and theoretical results yielded acceptable results

facilitates accurate theoretical modeling of CHF in in some but not all tests.

both straight and curved channels. Present

studies are focused on extending this model to

highly subcooled conditions. Rensselaer Polytechnic Institute

Center for Multiphase Research $126,920

Troy, NY 12180-3590 06-C

Rensselaer Polytechnic Institute 94-3

Dept of Mechanical Engineering, $ 0 Development of Multidimensional Two-Fluid

Aeronautical Eng & Mechanics 01-A Modeling Capability

Troy, NY 12180-3590 91-3 R. Lahey, Jr., D. Drew

Inelastic Deformation and Damage at High The work on the development of a

Temperature physically-based well-posed multidimensional

E. Krempl two-fluid model is continuing. A four-field model

has been proposed which is based on

A combined theoretical and experimental conservation equations for the evolution of

investigation is performed to study the biaxial continuous liquid, continuous vapor, dispersed

deformation and failure behavior of engineering liquid (droplets) and dispersed vapor (bubbles)

alloys under low-cycle fatigue conditions at fields

elevated temperature. The purpose is to

characterize the material behavior in mathematical The dispersed model is being extended to include

expressions that are intended for use in inelastic the effects of change of shape on the interfacial

Engineering Research 37 1995
forces, including virtual mass and lift. A new the second generation instrument is expected to

feature of the model is the interaction of the help plot more precise thickness profiles.

continuous vapor and the continuous liquid. Presently, the study of the formation of thin solid

Ensemble averaging concepts are being applied to films is being emphasized. Results obtained using

different interface configurations in order to derive the initial design were presented in Applied Optics,

closure conditions for interfacial momentum 33, pp 1223-1229, 1994, and, Physics Fluids, 6,

transfer and Reynolds stress. A model for droplet pp 1963-1971, 1994.

deposition has been developed and work is

continuing on entrainment, and coalescence and

break-up models. Rice University

Dept of Civil Engineering $88,000 Conservation equations for the evolution of Houston TX 77251 01-A

interfacial area density and curvature are being 95 3

developed to model the evolution of the interface A Novel Nonlinear System Identification

between the continuous liquid and the continuous Approach with Applicability to Aging of

vapor fields. The model is being derived for, and Energy Production and Distribution Systems

qualified against, Taylor bubbles and sinusoidal p Spanos

wavy interfaces.

Nonlinear forces acting on energy systems such

as large offshore structures, are studied from a

Rensselaer Polytechnic Institute perspective of system identification. The

Dept of Chemical Engineering $89,900 nonlinearities may be induced by ocean waves,

Troy, NY 12180-3590 01-C and they may become significant in several

93-4 situations. They are not necessarily assumed to

Development and Use of Image Scanning be in the form of Morison's equation. Various

Ellipsometer to Study the Dynamics of wave forces are examined. The force function is

Heated Thin Liquid Films decomposed either into a set of base functions, or

P. Wayner, Jr., J. Plawsky it is expanded in terms of the wave and structural

kinematics. The resulting nonlinear system is

The physicochemical phenomena associated with decomposed in a number of parallel non-memory,

fluid flow, change-of-phase heat transfer, and nonlinear systems, each followed by a finite

drying in ultra-thin (thickness less than 10-5 m) memory subsystem. A Gram-Schmidt

liquid films are being studied. In these thin liquid orthonormalization procedure is applied to

film systems, the interfacial, intermolecular, force decouple these subsystems; a frequency domain

field, which controls fluid flow and heat transfer, is technique involving auto-spectra and cross-spectra

a function of the film thickness profile. If the is employed to identify the linear transfer function.

physical properties of the evaporating liquid film In conjunction with this problem, an efficient

are known, the film thickness profile, measured algorithm for representing random processes by

experimentally, can be used to calculate the auto-regressive-moving-average digital algorithms

pressure field and the local evaporative heat is pursued for implementation into system

transfer rate. To measure the film thickness profile, identification problems. The analytical results are

a novel ellipsometric technique (Image Scanning calibrated by Monte Carlo simulation studies.

Ellipsometry, ISE) has been developed. ISE

combines classical null ellipsometry with

microscopic image processing, to determine University Of Rochester

simultaneously the thickness of the liquid film at all Dept of Physics and Astronomy $70,519

points on the substrate. Image processing helps Rochester, NY 14627 06-C

identify the precise location on the surface of the 95-3

liquid film which corresponds to the measured Flux Flow, Pinning, and Resistive Behavior

thickness. Thus a 2-D profile of the liquid film can in Superconducting Networks

be constructed. Currently, a second generation S. Teitel

ISE employing enhanced resolution image

acquisition and processing equipment is nearing The fluctuation of vortices and vortex lines has

completion. The augmented processing power of been shown to be a major source of electrical

Engineering Research 38 1995
resistance for superconducting networks when of the effects of the state of coherence of

placed in magnetic fields. Systems of particular fluctuating sources of radiation both on the spatial

interest include the new high temperature type II and on the spectral distribution of energy

superconductors, and periodic arrays of throughout the radiated field. Several significant

Josephson junctions. Numerical simulations are results have been obtained during the past year.

being carried out to identify and characterize the They include derivation of radiometric expressions

nature of the various vortex structures present in for the spectral density and the spectral flux vector

such systems, as a function of temperature and in fields generated by planar, secondary, quasiapplied magnetic field, and to understand the homogeneous sources. The results were applied

nature of the phase transitions between them. to elucidate the differences between radiometric

quantities associated with Lambertian and with

Particular attention has recently been given to Gaussian correlated sources. A radiometric model

studying the equilibrium fluctuation of vortex lines was also formulated for the propagation of

in models of bulk high temperature coherence, which greatly simplifies the

superconductors. determination of the degree of coherence of a

partially coherent field at arbitrary distances from

Simulations have shown that there can be two the source. New conservation laws for free

distinct phase transitions describing the electromagnetic fields of arbitrary state of

superconducting ordering parallel versus coherence were also formulated and some new

perpendicular to the applied magnetic field. The results on spectral invariance and non-invariance

loss of order in the perpendicular direction has were obtained. Properties of random pulses and

been associated with a melting of the ground state of other random fields were also investigated and

vortex line lattice. The loss of order in the parallel a relationship between the complex degree of

direction has been associated with the onset of a coherence in the space-time domain and in the

vortex line tangle percolating throughout the entire space-frequency domains were clarified.

system. New simulations, relaxing earlier

approximations, are being carried out to clarify this

issue. The effect of applied currents and random The Rockefeller University

vortex pinning sites will be added in future work. Department of Physics $89,000

The dynamic behavior of vortices in two 1230 York Avenue 06-C

dimensional Josephson arrays has also recently New York, NY 10021 95-4

been investigated using a detailed finite size

analysis to verify proposed scaling equations. Some Basic Research Problems Related to

Energy This research will greatly enhance the fundamental E Cohen

understanding of behavior in strongly fluctuating

superconducting materials. The results will have The present project is concerned with the following

impact in understanding the magnetic properties of problems

the new high temperature superconductors, and in

the design of Josephson junction arrays for use as 1. The Newtonian viscosity as well as the viscomicrowave detectors and generators. elastic (i.e., frequency dependent viscous)

behavior of monodisperse hard sphere colloidal

suspensions have been computed theoretically for

University Of Rochester all concentrations in the fluid range. A very simple

Dept of Physics and Astronomy $95,030 formula for the Newtonian viscosity is obtained,

Rochester, NY 14627 06-C which agrees very well with experiment. A Pade'-

93-3 approximant of this formula can facilitate its

Coherence Effects in Radiative Energy practical use. Similar expressions are obtained for

Transfer the visco-elastic behavior, which are consistent

E. Wolf with experiment.

This project is directed towards clarifying the 2. The investigation of Lorentz lattice gas cellular

foundations of radiometry and the theory of automata is continued. In this gas a point particle

radiative energy transfer and towards elucidation moves on the bonds of a lattice fully or partially

Engineering Research 39 1995
occupied by randomly placed scatterers. For fully velocity differences and the dynamically active

occupied lattices a mapping between the particle scalars. The mappings modify the velocity and

trajectories and percolation clusters (of a scalar profiles, yielding a self -contained evolution

corresponding percolation problem) can be made, process.

in that the former are the hulls of the latter. This

implies a scaling behavior of the trajectories. This formulation will be applied to homogeneous

However, also for partially occupied lattices, the turbulence, free shear flows, boundary layers, and

same scaling behavior of the particle trajectories is buoyant stratified flows to evaluate its predictive

observed, while no mapping to a percolation capability, both as a turbulence model and as a

problem can be made. To what extent this model of mixing in turbulent flow. The model will

behavior suggest a possible generalization of the be used to gain mechanistic understanding of

notion of percolation clusters, is being turbulent mixing processes involving passive and

investigated. active scalars.

3. Dynamical weights using expanding Lyapunov

exponents, rather than the usual probabilistic Sandia National Laboratories

(Gibbsian) weights, can be employed to obtain the Combustion Research Facility $25,000

probability distribution of a many particle system in Livermore, CA 94551-0969 06-B

a nonequilibrium stationary state (e.g. a sheared 90-3

fluid), which can be far from equilibrium. Inverse Diffusion Flames in Supercritical

Successful applications of this new approach to Water-Fuel Mixtures

obtain the properties of such a system have been R. Steeper

made and are further pursued.

This project investigates diffusion flames in

high-density fuel-water-oxidizer mixtures. These

Sandia National Laboratories hydrothermal flames are of practical concern in the

Combustion Research Facility $290,000 development of supercritical water oxidation

Thermofluids Division 06-B (SCWO) as a waste destruction process, but the

Livermore, CA 94550 93-3 basic scientific understanding of such flames is

limited. Sandia has built a laboratory-scale,

Molecular Mixing and Front Propagation hydrothermal flame reactor with optical access

in Turbulence suitable for imaging, laser velocimetry, and Raman

A. Kerstein spectroscopy diagnostics. Hydrothermal flames

created in this facility at supercritical conditions

The principal focus of this research program is exhibit characteristics distinct from

modeling of turbulent flows in which mixing atmospheric-pressure flames. The program

modifies flow energetics, as in buoyant stratified provides an opportunity to extend the basic

turbulence and turbulent combustion. Another scientific understanding of diffusion flames by

objective is determination of the structure and examining the effects of high density and an

mean rate of advance of fronts propagating aqueous environment.

through turbulence.

In experiments conducted to date, the range of

For the mixing problem, the modeling approach is initial concentrations and temperatures that lead to

an outgrowth of a method developed in work to the spontaneous ignition of methane-water-oxygen

date for application to turbulent mixing of and methanol-water-oxygen flames has been

dynamically passive scalars. That method mapped. A related series of experiments has

involves the representation of turbulence by determined spectroscopically the concentration

mappings applied to a one-dimensional scalar histories of methane, oxygen, carbon dioxide, and

profile. The mapping sequence is a stochastic carbon monoxide in reacting mixtures at

process reflecting pertinent features of the concentrations lower than the flame ignition

turbulent cascade. A generalization applicable to conditions. The latter data have yielded global

dynamically active scalars is obtained by reaction rates for SCWO of methane as a function

introducing a velocity profile. Now, the mappings of fuel/oxidizer concentrations, temperature, and

are determined by turbulence energetics based on water density. The global rates are an important

Engineering Research 40 1995
component of SCWO process design tools and flows can only be obtained if the dimensionless

serve as well to calibrate proposed elementary diffusion coefficient-concentration relationships are

reaction mechanisms. identical.

For very small Pe and constant diffusion

coefficients, the simulations show that a University Of Southern quasisteady state never forms. The finger tip soon

California becomes less well defined, and Taylor dispersion

Dept of Mechanical and $127,359 in Poiseuille flow is approached asymptotically.

Aerospace Engineering 01-C The unsteady evolution of this flow can be

Los Angeles, CA 90089 93-3 described based of some of Taylor's original

arguments. In particular, our results show that the

A Combined Experimental and Numerical asymptotic state is approached after a time of

Investigation of Multiphase Porous Media O(Pe), when the dimensionless concentration front

Flow Dynamics thickness has reached a length of O(Pe).

T. Maxworthy, E. Meiburg

Experimental and computational results have been Stanford University

derived for the displacement of a more viscous Dept of Mechanical Engineering $75,805

fluid by a less viscous one in a capillary tube and Stanford, CA 94305-3030 01-A

in a plane channel. For large values of the Peclet 93.3

number Pe, a quasisteady state forms, in which a Structure and Modelling of the Threefinger of the less viscous fluid proceeds down the Dimensional Boundary Layers on a Rotating

center of the tube, leaving behind a film of the Disk

more viscous phase on the wall of the tube. The J Eaton

finger tip is well defined and displays a steep

concentration front. For Atwood numbers near The objectives of this work are to develop

unity, the film thickness is approximately equal to improved understanding of the effect of mean flow

the value found by Taylor and Cox for immiscible three dimensionality on convective heat transfer

fluids and large capillary numbers. In this through detailed experiments on turbulent

parameter regime, experiments and computations transport mechanisms. Experiments have been

show excellent agreement. The film thickness conducted in two geometries, a large disk rotating decreases with At and depends only weakly on in still air and a highly skewed wind-tunnel

Pe. The quasisteady state persists for some time boundary layer. New miniaturized probes have

after the concentration boundary layers diffuse to been developed to measure the turbulent heat flux

the center of the tube at t-Pe. Eventually, the in the disk boundary layer. The probe uses a

finger tip decays, and the state of Poiseuille flow cross-wire anemometer with 2.5 micron diameter

and Taylor dispersion is approached wires and a separate resistance thermometer. A

asymptotically. technique has been developed for frequency

compensation of resistance thermometers that

For intermediate and lower values of Pe, there are allows their use to higher frequencies than

some discrepancies between the numerical previously possible. Temperature profiles have

simulations, which assume a constant diffusion been recorded and heat flux measurements are

coefficient, and the experiments, which show underway. An extremely high resolution

diffusion coefficients that can vary with laser-Doppler anemometer system was developed

concentration by almost two orders of magnitude. which provides a 35 micron diameter by 60 micron

Further numerical simulations with variable long measurement volume in a laboratory scale

diffusion coefficients have been carried out, and wind tunnel. Reynolds stress measurements deep

they lead to significantly improved agreement with into the sublayer of a skewed boundary layer were

the experiments. In particular, the variable acquired using this system. The results showed

diffusion coefficient simulations exhibit quasi- close alignment of the shear stress and strain rate

steady fingers at much lower values of Pe, in vectors near the wall. This contradicts previous

agreement with the experiments. These issues assumptions that were made in the absence of

show that true dynamical similarity of different any reliable data. The remainder of the grant

Engineering Research 41 1995
period will be used to complete the heat flux introduced by electric and magnetic coupling lead

measurements and interpret them in terms of to localized waves which can be significant in

available models. device design decisions. A second study of

dislocations in purely elastic joined anisotropic

crystals has revealed the existence of

Stanford University configurations in which dislocations on either side

Dept of Mechanical Engineering $135,000 of the bi-crystalline interface will be attracted to the

Stanford, CA 94305-3030 01-A interface. Such a situation (which we call mutual

95-3 attraction) is not possible when anisotropy is

Stress and Stability Analysis of Surface neglected and may play a significant role in the.

Morphology of Elastic and Piezoelectric trapping of dislocations at internal interfaces. A

Materials new study has focussed attention on determining

H. Gao, D. Barnett the equilibrium arrangements of large numbers of

dislocations in solids subjected to inhomogeneous

During the past year the part of our project on plastic deformation. The most interesting

stress-induced surface instability has entered a arrangements to initially examine are those at

new phase with the completion of the Ph.D. equilibrium under zero applied stress, which

degree by C-h Chiu who, in his thesis, presented corresponds to dislocation configurations existing

a comprehensive review of the state-of-the art after unloading. We have developed an

understanding of the formation of cusp-cracks by expression for the interaction energy between two

stress-controlled diffusion in solids. dislocations in an anisotropic solid as a necessary

Simultaneously an experimental study of surface ingredient for comparing a conjugate gradient

evolution in heteroepitaxial thin films has been method with more direct "zero-force" methods in

initiated. These experiments include Atomic Force numerical determinations of the equilibrium set.

and Electron Microscope studies of annealed The effect of different constraints (pinned

Si-xGe-1-x/Si (100) films with varying composition dislocations, glide constraints, stacking faults) on

and thickness. Subcritical film thicknesses have the determination of the equilibrium arrays will also

been considered to separate dislocation nucleation be investigated during the coming year.

processes from cusp formation processes. The

goal of these experiments is to check existing

theoretical predictions and further investigate the Stanford University

effect of surface instability on dislocation Edward L. Ginzton Laboratory $145,000

nucleation. The condition for stability/instability of Stanford, CA 94305-3030 03-B

surfaces in piezoelectric materials of arbitrary 93-3

elastic anisotropy has been determined and this Optical Techniques for Superconductor

work has been accepted for publication in and Thin Film Characteriztion

Proceedings of the Royal Society (London). It has G. Kino

been shown that piezoelectric coupling may either

stabilize or destabilize a flat surface, so that, in Photothermal measurements are used to study

theory, piezoelectric coupling could be utilized to diffusion and fluctuation phenomena in high temcontrol diffusive initiation of surface defects. perature superconductors. Phase delay

Experiments will be needed to verify the current measurements yield the thermal diffusion, and

theoretical model. Future work will be directed measurement of the reflectivity of the probe beam

toward corroborating theory with experiments and yields a quantity closely related to the specific

thereby identifying the need to develop better heat. Measurements have been made in

theoretical models for defect generation during individual crystallites 20-50 micrometers across.

stress-driven surface diffusion. Below Tc , the peak value of the diffusion constant

within a grain is much higher than in other

An investigation of Stoneley wave modes confined measurements, and it is in good agreement with

to the interface between two piezo-crystals theory. Above To, a very large temperature drop

(crystals exhibiting elastic-electric-magnetic is observed across grain boundaries in YBCO,

coupling) either bonded together or separated by indicating phonon reflection at the grain boundary.

an air gap or a superconducting layer has been We also observe a diffusion constant within an

completed. The new degrees of freedom individual crystallite of twice the normally

Engineering Research 42 1995
measured bulk value. Diffusion measurements environments, and are over an order of magnitude

below Tc in YBCO show good agreement with greater than those characteristic of low-pressure

experiments on measurements of normal electron systems.

density as a function of temperature. The

amplitude of the probing signal yields a quantity Recent experiments using DFWM to probe CH

closely related to the specific heat. In YBCO and and C2 within the reacting plasma have

Bi2Sr2CaCu 208, measurements show a large peak demonstrated the ability to provide sensitive (ppm

at Tc and a rapid fall-off from the peak value, in level) detection with submillimeter spatial

excellent agreement with the second-order phase resolution in the measurement of vibrational

transition theory for fluctuations near the critical temperatures, rotational temperatures, and species

point. Similar measurements of charge density concentrations.

waves in NbSe2 give good agreement with two-dimensional phase transition theory.

Stanford University

Dept of Chemistry $140,892 Stanford University Stanford, CA 94305 06-C

Mechanical Engineering Dept $206,887 95-4

Stanford, CA 94305 03-B Topics in a Thermodynamic and Stochastic

92-4 Theory of Nonlinear Processes Far from

Advanced Diagnostics for Plasma Chemistry Equilibrium

C. Kruger, T. Owano J. Ross

This research is concerned with optical diagnostics Research focuses on the thermodynamic and

for plasma chemistry and plasma processing, with stochastic theory of hydrodynamic processes, such

an emphasis on methods that allow for departures as combinations of chemical reactions, diffusion,

from local thermodynamic equilibrium (such as thermal conduction, and viscous flow. Such

finite chemical reaction rates, nonequilibrium theories have been formulated for each of the

electron densities and temperatures, and radiation individual processes, both linear and nonlinear.

loss effects). Studies in an induction plasma Progress has been made on combinations of

facility show significant nonequilibrium within a these processes for a simplified form of the

downstream reactor, and suggest the possibility of Navier-Stokes equations, the so-called Lorenz

erroneous results when using conventional equations. The theory leads to a formulation of an

diagnostics that assume local thermodynamic excess work expressed in terms of thermodynamic

equilibrium. functions, which provides a Liapunov function,

necessary and sufficient conditions of stability,

Advanced laser-based methods are being criteria of relative stability, and relations to

developed for measurement of plasma parameters fluctuations. An extensive model of chemo-taxis

including species concentration and temperature. has been formulated with detailed accounts of

The primary technique under study is the extensive experiments. The model accounts

application of Degenerate Four-Wave Mixing quantitatively for exact adaptation, initial response,

(DFWM) to atmospheric pressure plasma and chemical thermodynamic motion.

environments in order to assess the importance of

nonequilibrium effects under conditions of interest

to plasma chemistry. Cavity Ring-Down Stanford University

Spectroscopy (CRDS) is also under investigation Dept of Chemistry $ 0

as another non-intrusive diagnostic. Stanford, CA 94305 03-A

92-4 To investigate the application of advanced laser Degenerate Four-Wave Mixing as a

diagnostics to a realistic and promising form of Diagnostic of Plasma Chemistry

plasma processing, experiments have been R. are R. Zare

undertaken on the reacting plasma boundary layer

of a substrate placed in a diamond producing This research pioneers a new absorption

plasma flow. Linear growth rates up to 50 technique, called cavity ring-down spectroscopy

Im/hour have been demonstrated in these ((CRDS), as a means to provide highly sensitive

Engineering Research 43 1995
measurements of absolute concentrations of the time symmetry is broken as the result of

species in plasmas and other luminous media. A complex eigenvalues of the extended Liouvillian.

CRDS apparatus has ben designed to measure Irreducible means that these representations

the trace radical species generated in a hot- cannot be implemented by trajectories or

filament reactor for diamond film deposition and wavefunctions; therefore, laws of nature take a

the in situ measurement of methyl radicals in the new form, as they have to be formulated on the

reactor has been successfully carred out under statistical level. They express "possibilities" and

various growth conditions. A radial profile of the no longer "certitudes." For integrable systems, our

CH3 absolute concentration near the hot filament theory recovers the usual formulations of classical

has been determined by CRDS using the Abel or quantum mechanics. Hence, this extension of

inversion of the spatial profile of CH3 absorbance. dynamics permits us to unify the two concepts of

nature, based one on dynamical time-reversible

The research includes the determination of the laws and the other on the evolutionary view

conditions under which CRDS can be used for associated to entropy. It also leads to a unified

quantitative measurement of absolute formulation of quantum theory, avoiding

concentrations of molecular species. The conventional dual structure based on

conditions useful for CRDS diagnostics have been Schrodinger's equation on the one hand, and on

estimated by analyzing how the absorption loss the "collapse" of the wave function on the other.

measured by CRDS varies with the sample There is striking parallelism between classical and

absorbance for various ratios of the laser pulse quantum theory. In general, for LPS, both a

linewidth to the absorption linewidth. A wide range "collapse" of trajectories and of wave function

of conditions was found in which the sample exist; this theory predicts a number of new

absorbance (and, consequently, absolute number phenomena for LPS, as well as chaotic maps,

densities) can be recovered from the CRDS which have no correspondence in the traditional

spectrum. description by trajectories or wavefunctions. It

also goes beyond phenomenological kinetic

theory. Numerical simulations verify our

University Of Texas At Austin predictions.

Ctr for Studies in Statistical Mech $ 0

and Complex Systems 06-C

Austin, TX 78712 94-3 University Of Texas At Austin

Dept of Physics $358,475

The Behavior of Matter Under Non- Austin, TX 78712 06-C

Equilibrium Conditions: Fundamental 93-5

Aspects and Applications Complex Spatiotemporal Patterns in

I. Prigogine, T. Petrosky Nonequilibrium Systems

H. Swinney

Both classical and quantum mechanics can be

described either on the individual level (in terms of The formation of time-dependent spatial patterns

trajectories or wavefunctions) or on the statistical is being studied in chemical and physical systems

level using the Liouville operator. It has maintained far from equilibrium. The goal is to

traditionally been assumed that these two understand what features of behavior are common

descriptions are equivalent; however, this is no in diverse pattern-forming systems. What kinds of

longer true for unstable dynamical systems such patterns arise spontaneously as the stress is

as associated to deterministic chaos or to increased on an initially homogeneous system?

Poincare nonintegrable systems with continuous What kinds of transitions are permitted between

spectrum (so-called Large Poincare systems, different patterns? What is the role of symmetries

LPS). Practically all systems studied in statistical in the boundary conditions and the equations of

mechanics belong to this class. To describe these motion? These issues are being addressed in

systems, one has to introduce delocalized laboratory experiments and numerical simulations

ensembles that lie outside the Hilbert space. on reaction-diffusion systems, vertically vibrated

Once the Liouvillian is extended outside the Hilbert granular media, a convecting fluid, and chemical

space, complex, irreducible spectral electrodeposition. The experiments on chemical

representations are obtained. Complex means that patterns have yielded new examples of spatial and

Engineering Research 44 1995
spatiotemporal symmetry breaking transitions. An 2. Work on the effective elastic properties of

experiment on a vertically vibrated shallow layer materials with holes of arbitrary shapes was

has revealed transitions to striped, square, started. Preliminary results have been obtained

hexagonal, and disordered patterns; a model with for holes of elliptical shapes.

a single dissipative layer yields insight into this

transition sequence. Comparison of the laboratory

observations with simple models provides general University of Washington

insights into the formation of spatiotemporal Dept of Mechanical Engineering $69,975

patterns. Seattle, WA 98195 01-A

94-3

3-D Experimental Fracture Analysis Tufts University at High Temperatures

Dept of Mechanical Engineering $ 0 A. Kobayashi

Medford, MA 02155 01-A

92-3 The objective of this three year research project is

Effective Elastic Properties and to assess experimentally, the validity of T* integral

Constitutive Equations for Brittle and its applicability to quasi-static and dynamic

Solids Under Compression ductile fracture analyses. During this first year, the

M. Kachanov surface displacement fields, which was determined

by moire interferometry, of A606 HSLA steel

Work done under the contract concentrated on the single-edge notched (SEN) specimens with small

following problems. stable crack growth of Aa = 2 mm, were used to

compute directly the T* integral for various domain

1. Investigations of the mechanics of defects in integrals surrounding the crack tip. J was also

an anisotropic environment. This investigation, obtained for several outer contours. The smallest

rather broad in scope, includes the following inner contour, G,, of the domain integral was

topics: limited to 6 mm due to the dense moire fringes in

the immediate vicinity of the crack tip. Elastic-

(a) The impact of matrix anisotropy on the plastic finite element analysis (FEA), which was

mechanics of crack interactions. It was found, in conducted at Georgia Institute of Technology

particular, that the matrix anisotropy enhances the under a parallel DOE grant, of the same SEN

interactions if loading is applied along the stiffer specimen for a larger crack extension of Aa = 8.5

direction of the matrix, and that it weakens the mm showed that J was highly path dependent but

interactions if loading is applied along the softer T* remained path independent with stable crack

direction of the matrix. This effect is strongly growth. Also the experimentally determined T*

asymmetric; the enhancement effect is much were in good agreement with the corresponding

more pronounced than the weakening effect. values obtained by FEA. The computed and

measured CTOA were in excellent agreement and

(b) The mechanics of crack-microcrack remained a constant 15° after dropping from an

interactions in an anisotropic environment. A initial high of 30° possibly due to crack tip

variety of representative geometries was examined blunting.

and the impact of different elastic constants of the

matrix was analyzed. A series of experiments using a moire grating of

10 lines/mm on central notched (CN) specimens

(c) The effective elastic properties of anisotropic will be undertaken shortly. It is hoped that this

matrices with arbitrarily oriented and interacting coarser grating on a specimen configuration with

cracks. larger constraint will provide moire interferometry

fringes closer to the crack tip, i.e. about 1 mm,

and also for a longer crack extension of about Da

= 6 mm.

Engineering Research 45 1995
Washington University vortex structures which are a dominant component

Department of Systems Science $77,434 of free shear flows. Although three dimensional

and Mathematics 03-A vortex structures can be quite complex in nature

Saint Louis, MO 63130 93-3 time scaling quantities such as Stokes number can

still be expected to be important for understanding

Visually Guided Control Systems: A New the experimental and numerical results concerning

Generation of System Analysis and Design the particle dispersion process.

B. Ghosh

This research program is employing time

The main objective of the proposed project is to dependent experimental and numerical techniques

study dynamical systems that are controlled with to provide information concerning the particulate

the aid of CCD cameras. Such a class of dispersion process produced by three- dimensional

systems, called "Visually Guided Control Systems," v o rt ex structures. The free shear flows

have the capability to use visual information to investigated include modified plane mixing layers,

provide sutomatic feedback control to a and modified plane wakes. The modifications to

dynamically moving system. An example of such these flows involve slight perturbations to the

a system is a robotic manipulator with a set of initiation boundary conditions such that

cameras attached operating in an unstructured three-dimensional vortex structures are rapidly

environment. generated by the experimental and numerical flow

fields. The particulate dispersion process

We propose a new dynamical systems approach associated with these three-dimensional flow

to vision and to vision-based control system structures will be intensively studied to obtain

design problems that is new both to the area of understanding which may lead to improving the

Computer Vision and to the area of Control design and performance of many energy

System Design. The propsed project, based on a conversion systems.

new theory of "Prospective Systems," promises to

enrich the field of Computer Vision especially in

the area of Motion and Shape estimation of University Of Wisconsin

dynamically moving objects in an environment. It Mechanical Engineering Dept $122,000

also introduces new challenges in System Theory, Milwaukee, WI 53201 01-C

wherein feedback control is generated by visual 93-3

sensors based on the theory of nonlinear Interfacial Area and Interfacial Transfer in

regulation and nonlinear optimal control. The Two-Phase Flow Systems

proposed project undoubtedly broadens the G. Kojasoy

technology and conceptual base while introducing

some new promising approaches to visually- The objectives of the proposed research program

guided control systems. are to develop instrumentation methods, an

experimental data base, and an analysis leading to

predictive models for describing the interfacial

Washington State University structure and behaviors of horizontal two-phase

Dept of Mech & Matls Engineering $74,420 flows. In terms of the flow structure, the

Pullman, WA 99164-2920 01-B transverse distributions of the local void fraction,

l94-n3 interfacial area concentration, fluid particle size

Coupled Particle Dispersion by Three- and their axial development from the entrance to

Dimensional Vortex Structures the exit will be the primary focal point of the

T. Troutt research. For the purpose of understanding the

dynamic behaviors, the interfacial velocity, wave

The primary objective of this research program is characteristics, fluid particle coalescence and

to obtain understand concerning the role of disintegration will be studied. The axial changes

three-dimensional vortex structures in the in the distribution of void fraction and interfacial

dispersion of particles and droplets in free shear area give the information on the particle

flows. This research study builds on previous coalescence and disintegration. These will be

studies which focused on the nature of particle characterized by the collision frequency and

dispersion in large scale quasi two-dimensional interfacial energy and turbulence in the liquid.

Engineering Research 46 1995
A special emphasis will be placed on the further developing process identification and control

improvement of the multi-sensor resistivity probe procedures which allow the design of advanced

method which has been successfully developed control systems based on limited process

and cross-calibrated against other global information and which will work reliably when

techniques. The multi-sensor probes will be used process parameters change in an unknown

together with hot-film probes for the liquid manner. Specific topics to be studied include new

turbulence measurements. These new process identification procedures, nonlinear

measurements will give sufficient information to controller designs, adaptive control methods, and

evaluate the local relative velocity and momentum techniques for distributed parameter systems.

interaction between phases. Final focus of the Both fundamental and immediately applicable

modeling effort is to develop interfacial area results are expected. The theoretical

transport equation which incorporates the developments are being tested experimentally on

mechanistic models for coalescence and pilot scale equipment in the laboratory. These

disintegration of fluid particles. This transport experiments not only allow improvements in

equation describes dynamical change of the theoretical work, but also represent real life

interfacial structure and replaces the conventional demonstrations of the effectiveness of the

model based on flow regime transition criteria. methods and of the feasibility of implementing

them in an industrial environment. The new

The proposed research program will provide: a) a techniques developed in this project will be

new scientific instrumentation method for studying incorporated into computer-aided design packages

detailed interfacial characteristics of two-phase and disseminated to industry. Therefore, it is

flow, b) benchmark data for the local interfacial expected that the work will have an impact on

area concentration, void fraction distribution, industrial practice.

interfacial wave structure, relative velocity and

wave propagation velocity for horizontal two-phase

flow systems, c) mechanistic models for fluid

particle coalescence and disintegration, and d)

interfacial area transport equation.

University Of Wisconsin

Dept of Chemical Engineering $119,340

Madison, Wl 53706 03-A

92-3

New Process Modeling, Design, and

Control Strategies for Energy Efficiency,

High Product Quality, and Improved

Productivity in the Process Industries

W. Ray

The process industries are having great difficulty

competing in the world market because of high

energy costs, high labor rates, and old technology

for many processes. This project is concerned

with the development of process design and

control strategies for improving energy efficiency,

product quality, and productivity in the process

industry. In particular, (1) the resilient design and

control of chemical reactors, and (2) the operation

of complex processing systems, will be

investigated. Major emphasis in part (1) will be on

two important classes of chemical reactors:

polymerization processes and packed bed

reactors. In part (2), the main focus will be on

Engineering Research 47 1995
Budget Number Index

Mechanical Sciences:

01-A Solid Mechanics: macroscopic aspects of elastic and plastic deformations,

and crack propagation

01-B Heat Transfer

01-C Fluid Mechanics

01-D Tribology

Control Systems and Instrumentation:

03-A Control systems, large scale systems

03-B Instrumentation for hostile environment, and NDE

03-C Intelligent systems

Engineering Data and Analysis:

06-A Thermophysical properties and processes

06-B Combustion

06-C Non-linear dynamics and engineering analysis
Budget Page

Number Number

01-A

Chaos in Fluid-Structure Systems .................................... 1

Continuum Damage Mechanics - Critical States .......................... 2

An Investigation of History Dependent Damage in Time Dependent

Fracture M echanics ............................................. 3

Simulation and Analysis of Dynamic Failure of Ductile Materials .............. 3

Nonlinear Dynamics of Fluid-Structure Systems .......................... 12

An Analytical-Numerical Alternating Method for 3-D Inelastic Fracture and

Integrity Analysis of Pressure-Vessels and Piping at Elevated Temperature ...... 14

Elastic-Plastic Fracture Analysis Emphasis on Surface Flaws ................. 16

Stress Induced Phase Transformations ............. ................... 18

Modeling and Analysis of Surface Cracks .............................. 23

Inelastic Deformation and Damage at High Temperature ................... 37

A Novel Nonlinear System Identification Approach with Applicability to

Aging of Energy Production and Distribution Systems ..................... 38

Structure and Modelling of the Three-Dimensional Boundary Layers

on a Rotating D isk ............................................. 41

Stress and Stability Analysis of Surface Morphology of Elastic

and Piezoelectric M aterials ........................................ 42

Effective Elastic Properties and Constitutive Equations for Brittle

Solids Under Compression ........................................ 45

3-D Experimental Fracture Analysis at High Temperature ................... 45

01-B

Film Cooling in a Pulsating Stream .................................. 2

Ultrashort laser Heating and Phase Change in Liquids ...................... 4

Heat/Mass Transfer Enhancement in Separated Vortex Flows ................. 25

Theory of Subcooled Boiling ....................................... 3(

Radiative Transfer Through Arrays of Discrete Surfaces with Fixed Orientation .... 34

Research on Combustion-Driven HVOF Thermal Sprays .................... 35

Near-Wall Measurement of Sublayer Dryout and Theoretical Modeling of

CHF in Vertical Channels ........................................ 37

Coupled Particle Dispersion by Three-Dimensional Vortex Structures ........... 46

01-C

Hydrodynamic Instabilities and Coherent Structures ........................

Basic Studies of Transport Processes in Porous Media ...................... 5

W ave Turbulence Interactions ....................................... 9

Gas and Solids Holdup in Three Phase Bioreactors ........................ 11
01-C (cont'd)

Experimental Studies of Reynolds Number Dependence of Turbulent Mixing

and Transport ................... .............................. 13

Two-Phase Potential Flow ......................................... 13

Experimental and Analytical Investigations of Flows in Porous Media ........... 13

Gas-Liquid Flow in Pipelines ....................................... 17

Numerical and Physical Modelling of Two-Phase Flow Phenomena at Large

Reynolds Num bers ............................................. 18

Turbulence Theory ............................................. 19

Contaminant Dispersal in Bounded Turbulent Shear Flows ................... 21

Rheological and Flow Characteristics of Dense Multiphase Slurries Employing a

Bim odal M odel ............................................... 24

Lubricated Transport of Viscous Materials .............................. 26

Microscopic Interfacial Phenomena During Flow in Porous Media ............. 31

Wave Dynamics on Falling Films and Its Effects on Heat/Mass Transfer ......... 32

Active Control of Convection ....................................... 34

Effect of Forced and Natural Convection on Solidification of Binary Mixtures ..... 36

Interfacial Area and Interfacial Transfer in Two-Phase Flow .................. 36

Development and Use of Image Scanning Ellipsometer to Study the Dynamics

of Heated Thin Liquid Films ...................................... 38

A Combined Experimental and Numerical Investigation of Multiphase

Porous M edia Flow Dynamics ..................................... 41

Interfacial Area and Interfacial Transfer in Two-Phase Flow Systems ........... 46

01-D

Characterization of Metal Cutting Dynamics ............................. 20

Cryotribology (Low Temperature Friction and Wear) Development of

Cryotribological Theories and Application to Cryogenic Devices ............. 23

03-A

M odeling for Process Control ....................................... 9

Dynamic Failure Characterization of Ductile Steels ........................ 10

Systematic Process Synthesis and Design Methods for Cost Effective Waste

M inim ization ................................................. ()

Application of Intelligent Control Systems to Mixed-Culture Bioprocesses ........ 15

Intelligent Control of Thermal Processes ............................... 16

Model Building, Control and Optimization of Large Scale Systems ............. 17

Synthesis and Optimization of Chemical Processes ........................ 22

Partial Control of Complex Processing Systems .......................... 29

Degenerate Four-Wave Mixing as a Diagnostic of Plasma Chemistry ............ 43

Visually Guided Control Systems: A New Generation of

System Analysis and Design ....................................... 46

New Process Modeling, Design and Control Strategies for Energy Efficiency,

High Product Quality, and Improved Productivity in the Process Industries ...... 47
03-B

Nondestructive Evaluation of Superconductors ........................... 17

Two-Phase Flow Measurements by NMR ............................... 20

Pulse Propagation in Inhomogeneous Optical Waveguides ................... 21

Metal Transfer in Gas Metal Arc Welding .............................. 22

Multivariable Control Of The Gas-Metal Arc Welding Process ................ 23

Development of Measurement Capabilities for the Thermophysical

Properties of Energy-Related Fluids .................................. 28

Thin-Film Characterization and Flaw Detection ........................... 30

Optical Techniques for Superconductor and Thin Film Characterization .......... 42

Advanced Diagnostics For Plasma Chemistry ............................ 43

03-C

Research on a Reconfigurable and Reliable Manipulators .................... 11

Center for Engineering Systems Advanced Research (CESAR) ................ 33

06-A

Enzyme Adsorption and Activity at Liquid-Liquid Interfaces ................. 3

Fundamentals of Thermal Plasma Processing ............................ 15

Modeling of Thermal Plasma Processes ................................ 15

Steady State and Transient Nucleation Kinetics ........................... 19

Development of Principles and Methodologies of Metabolic Engineering ......... 24

Gelation of Dense Silica Suspensions Effect of Shear ...................... 27

A Study of the Mechanisms of Liquid-Liquid Emulsion Bioreactor Systems ....... 33

Transport Properties of Disordered Porous Media From The Microstructure ....... 35

06-B

Fundamental Studies of Spray Combustion .............................. 6

Mechanisms and Enhancements of Flame Stabilization ...................... 35

Molecular Mixing and Front Propagation in Turbulence ..................... 40

Inverse Diffusion Flames in Supercritical Water-Fuel Mixtures ................ 40

06-C

Dynamics of Electronegative Plasmas for Materials Processing ................ 4

Linear Kinetic Theory and Particle Transport in Stochastic Mixtures ............ 5

Nonlinear Waves in Continuous Media ................................ 6

Broadband Signals: Signal Processing in Chaos ........................... 6

Noisy Nonlinear Systems ............................. ............. 7
06-C (cont'd)

Structure of Turbulence, Conditional Averaging and Subgrid-Scale Modeling ...... 7

Traveling-Wave Convection in Fluid Mixtures ........................... 8

Modeling of Process Control ........................................ 8

Bifurcations and Patterns in Nonlinear Dissipative Systems .................. 8

Fundamentals and Techniques of Nonimaging Optics ....................... 11

Studies in Nonlinear Dynamics ...................................... 19

Mathematical Models of Hysteresis .............................. .... 21

Macrostatistical Hydrodynamics .................... ................. 25

Thermal Plasma Processing of Materials ............................... 26

Department of Energy Integrated Manufacturing Fellowship Program ........... 27

Center for Aerospace Research & Education for Minority Students at

Southern University ............................................ 27

High-Tc Superconductor-Semiconductor Integration and Contact Technology ...... 28

The Rheology of Concentrated Suspensions .................. ........... 28

Studies in Physico-Chemical Hydrodynamics of Extended Systems ............. 29

Sub-Electron Transfer of Electric Charge in Semiconductor Nanostructure ........ 30

Fragmentation and Dispersion of Powdered Solids in Viscous Liquids ........... 31

Stability and Dynamics of Spatio-Temporal Structures ...................... 32

Development of Multidimensional Two-Fluid Modeling Capability ............. 37

Flux Flow, Pinning, and Resistive Behavior in Superconducting Networks ........ 38

Coherence Effects in Radiative Energy Transfer ........ ............ 39

Some Basic Research Problems Related to Energy ........................ 39

Topics in a Thermodynamic and Stochastic Theory of Nonlinear Processes

Far from Equilibrium ................. .......................... 43

The Behavior of Matter Under Nonequilibrium Conditions: Fundamental

Aspects and Applications ......................................... 44

Complex Spatiotemporal Patterns in Nonequilibrium Systems ................. 44
Principal Investigators

Investigator Page No.

H. Abarbanel Phone: (619) 534-5590; Fax: (619) 534-7664; e-mail: habarbanel@ucsd.edu ................. 6

J. Achenbach Phone: (708) 491-5527; Fax: (708) 491-5227; e-mail: achenbach@nwu.edu .................. 30

A. Acrivos Phone: (212) 650-8159; Fax: (212) 650-6835; e-mail: chemw@ccnyvne .................... 28

G. Ahlers Phone: (805) 964-4813; Fax: (805) 964-4170; e-mail: guenter@tweedledum.ucsb.edu ........... 8

S. Altobellli Phone: (505) 262-7155; Fax: (505) 262-7043; ....................................... 20

S. Atluri Phone: (404) 894-2758; Fax: (404) 894-2299; ....................................... 14

S. Banerjee Phone: (805) 893-3456; Fax: (805) 893-4731; e-mail: banerjee@anemone.ucsb.edu ............. 9

S. Bankoff Phone: (708) 491-5267; Fax: (708) 491-3728; e-mail: gbankoff@casbah.acns.nwu.edu ......... 30

J. Barhen Phone: (423) 574-7131; Fax: (423) 574-0405; e-mail: barhen@ornl.gov . ............. 33

D. Barnett Phone: (415) 723-4143; Fax: (415) 725-4034; e-mail: barnett@leland.stanford.edu ......... 42

P. Barton Phone: (617) 253-6526; Fax: (617) 258-5042; e-mail: pib@mit.edu ........................ 22

T. Basar Phone: (217) 333-3607; Fax: (217) 244-1653; e-mail: tbasar@bllack.csl.uiuc.edu ......... 17

H. Bau Phone: (215) 898-8363; Fax: (215) 573-2065; e-mail: bau@eniac.seas.upenn.edu .............. 34

R. Behringer Phone: (919) 660-2550; Fax: (919) 660-2525; e-mail: bob@phy.duke.edu ................. 13

B. Berger Phone: (301) 405-5283; Fax: (301) 314-9477; e-mail: berger@eng.umd.edu .................. 20

P. Bernard Phone: (301) 405-5272; e-mail: bernard@eng.umd.edu ................................ 21

L. Biegler Phone: (412) 268-2232; Fax: (412) 268-7139;e-mail: biegler@cmu.edu ..................... 10

H. Blanch Phone: (510) 642-1387; Fax: (510) 642-4778; e-mail: blanch@cchem.berkeley.edu ............. 3

I. Blankson Phone: (202) 358-4610; ...................................................... 27

H. Brenner Phone: (617) 253-6687; Fax: (617) 258-8224; e-mail: hbrenner@nmit.edu .................... 25

F. Brust Phone: (614) 424-5034; Fax: (614) 424-3457; e-mail: brust@emrbattelle.org ................. 3

D. Cannell Phone: (805) 964-4813; Fax: (805) 964-4170; ....................................... 8

A. Caprihan Phone: (505) 262-7155; Fax: (505) 262-7043; ....................................... 20

I. Catton Phone: (310) 825-5320; Fax: (310) 206-4830; e-mail: catton@seas.ucla.edu .................. 5

C. Chang Phone: (208) 526-2886; Fax: (208) 526-6970; e-mail: chc@inel.gov ....................... 15

H. Chang Phone: (219) 631-5697; Fax: (219) 631-8366; e-mail: hsueh-chia.chang.2@nd.edu ............. 32

S. Chen Phone: (708) 252-6147; Fax: (708) 252-5568; .......................................

E.G.D. Cohen Phone: (212) 327-8855: Fax: (212) 327-8507; ....................................... 39

S. Davis Phone: (708) 491-5397; Fax: (708) 491-2178; e-mail: sdavis@nwu.edu ..................... 30

D. Drew Phone: (518) 276-6903; Fax: (518) 276-4824; e-mail: drewd@rpi.edu ...................... 37

K. Drost Phone: (509) 375-2017; ...................................................... 34

T. Eagar Phone: (617) 253-3229; Fax: (617) 258-6118; e-mail: tweagar@mit.edu .................... 22

J. Eaton Phone: (415) 723-1971; Fax: (415) 723-4548; e-mail: eaton@sierra.stanford.edu ............... 41

J. Ekin Phone: (303) 497-5448; e-mail: ekin@boulder.nist.gov ................................ 28

J. Epstein Phone: (208) 526-6874; Fax: (208) 526-0690; e-mail: jse@inel.gov ........................ 16

L. Evans Phone: (617) 577-0100; Fax: (617) 577-0722; e-mail: evans@aspentec.com .................. 22

H. Fasel Phone: (520) 621-2771; Fax: (520) 621-8191; e-mail: fasel@ccit.arizona.edu ................. 2

J. Fincke Phone: (208) 526-2031; Fax: (208) 526-2814; e-mail: jfl@inel.gov ........................ 15

A. Frenkel Phone: (205) 348-5434; Fax: (205) 348-7067; e-mail: afrenkel@gp.as.ua.edu .................

L. Freund Phone: (401) 863-1476; Fax: (401) 863-1157 ....................................... 3

E. Fukushima Phone: (505) 262-7155; Fax: (505) 262-7043; e-mail: eiichi@lucy.tli.org .................... 20

H. Gao Phone: (415) 725-2560; Fax: (415) 723-1778; e-mail: gao@am-sun2.stanford.edu .............. 42

J. Georgiadis Phone: (217) 244-7578; Fax: (217) 333-1942; e-mail: jgeorgia@usch.cso.uine.edu ............. 13

B. Ghosh Phone: (314) 935-6039; Fax: (314) 935-6121; ....................................... 46

R. Goldstein Phone: (612) 625-5552; Fax: (612) 625-3434; e-mail: rjgumnl@mailbox.mail.umn.edu ........... 25

A. Graham Phone: (505) 665-5259: Fax: (505) 665-9521; e-mail: graham@lanl.gov .................... 25

I. Grossman Phone: (412) 268-2228; Fax: (412) 268-7139;e-mail: grossman@cmu.edu ................... 10

H.J.M. Hanley Phone: (303) 497-3320; Fax: (303) 497-5044; e-mail: hanley@central.bldrdoc.gov ............. 27

T. Hanratty Phone: (217) 333-1318; Fax: (217) 244-8068; ....................................... 17

D. Hardt Phone: (617) 253-2252; Fax: (617) 252-2123; e-mail: hardt@mit.edu ...................... 23
Principal Investigators (cont'd - pg. 2)

W. Haynes Phone: (303)497-3247; .......................... ........................... 28

J. Heberlein Phone: (612) 625-4538; Fax: (612) 624-1398; e-mail: jvrh@me.unm.edu .................... 26

F. Incropera Phone: (317) 494-5688; Fax: (317) 494-0539; e-mail: incroper@nm.ecn.purdue.edu ............ 36

M. Ishii Phone: (317) 494-4587; Fax: (317) 494-9570; ....................................... 36

Y. Iwasa Phone: (617) 253-5548; Fax: (617) 253-5405; e-mail: iwasa@jokaku.pfc.mit.edu .............. 23

G. Johnson Phone: (919) 660-2711; Fax: (919) 681-8648; e-mail: gaj@orion.mc.duke.edu ................ 13

J. Johnson Phone: (208) 526-9021; Fax: (208) 526-0690; e-mail: jsq@inel.gov ....................... 15

D. Joseph Phone: (612) 625-1801; Fax: (612) 626-1558 ....................................... 26

M. Kachanov Phone: (617) 627-3318; Fax: (617) 627-3819; ....................................... 45

T. Kanade Phone: (412) 268-2454; Fax: (412) 268-2860 ....................................... II

A. Kaufman Phone: (510) 486-7889;. Fax: (510) 486-7550; e-mail: ankaufman@lbl.gov ................... 19

R. Kayser Phone: (301) 975-2483; Fax: (301) 869-4020; e-mail: kayser@micf.nist.gov .................. 28

A. Kerstein Phone: (510) 294-2390; Fax: (510) 294-1004; e-mail: kerstein@ca.sandia.gov ................ 40

P. Khosla Phone: (703) 696-2218; Fax: (703) 696-2202 ....................................... 11

G. Kino Phone: (415) 723-0205; Fax: (415) 725-7509; e-mail: kino@sierra.stanford.edu ............... 42

A. Kobayashi Phone: (206) 543-5488; Fax: (206) 685-8047; e-mail: ask@u.washington.ed .................. 45

G. Kojasoy Phone: (414) 229-5191; Fax: (414) 229-6958; ....................................... 46

R. Kraichnan Phone: (505) 986-3979; Fax: (505) 989-4737; e-mail: rhk@lanl.gov ....................... 19

D. Krajcinovic Phone: (602) 965-8656; Fax: (602) 965-1384; e-mail: knap@asu.edu ............. ......... 2

E. Krempl Phone: (518) 276-6351; Fax: (518) 276-6025; e-mail: krempe@rpi.edu ..................... 37

C. Kruger Phone: (415) 723-0977; Fax: (415) 725-1653; e-mail: kruger@soe.stanford.edu ............... 43

T. Lahey Phone: (518) 276-6203; Fax: (518) 276-8788; e-mail: laheyr@rpi.edu ...................... 37

J. Lang Phone: (617) 253-4687; Fax: (617) 258-6774; e-mail: lang@mit.edu ....................... 22

C. Law Phone: (609) 258-5271; Fax: (609) 258-6233; e-mail: cklaw@princeton.edu .................. 35

J. Levelt-Sengers Phone: (301) 975-2463; ...................................................... 28

P. Libby Phone: (619) 534-3168; Fax: (619) 534-4543; e-mail: lihby@ames.ucsd.edu .................. 6

A. Lichtenberg Phone: (510) 642-4015; Fax: (510) 642-6330; e-mail: ajl@eecs.berkeley.edu ................. 4

M. Lieberman Phone: (510) 642-7200; Fax: (510) 642-6330; e-mail: lieber@eecs.berkeley.edu ............... 4

K. Likharev Phone: (516) 632-8159; Fax: (516) 632-8774 ....................................... 30

K. Lindenberg Phone: (619) 534-5489; Fax: (619) 534-6693; e-mail: klindenberg@ucsd.edu ................. 7

R. Littlejohn Phone: (510) 486-7901; Fax: (510) 486-7550; e-mail: rglittlejohn@lbl.gov ................... 19

W. Lloyd Phone: (208) 526-0808; Fax: (208) 526-8006; e-mail: qrl@inel.gov ........................ 16

F. McClintock Phone: (617) 253-2219; Fax: (617) 258-8742; ....................................... 23

J. McLaughlin Phone: (315) 268-6663; Fax: (315) 268-6654; e-mail: jmclau@sun.soe.clarkson.edu ............ 11

T. Maxworthy Phone: (213) 740-0481; Fax: (213) 740-7774; e-mail: maxworth@mizar.usc.edu ............... 41

J. Mayergoyz Phone: (301) 405-3657; Fax: (301) 314-9281; e-mail: isaak@eng.umd.edu ................... 21

E. Meiburg Phone: (213) 740-5376; Fax: (213) 740-7774; e-mail: eckart@spock.usc.edu ................. 41

C. Menyuk Phone: (410) 455-3501; Fax: (410) 455-6500; e-mail: menyuk@umbc.edu ................... 21

M. Miksis Phone: (708) 491-5585: Fax: (708) 491-2178; e-mail: miksis@nwu.edu ..................... 31

I. Minis Phone: (301) 405-5310: Fax: (301) 314-9477; e-mail: minis@src.umd.edu ................... 20

M. Moldover Phone: (301) 975-2459; ...................................................... 28

L. Mondy Phone: (505) 844-1755; Fax: (505) 844-8251; e-mail: lamondy@sandia.gov .................. 25

F. Moon Phone: (607) 255-7146; Fax: (607) 255-1222 ....................................... 12

M. Morari Phone: (818) 395-4115; Fax: (818) 568-8743; e-mail: morari@caltech.edu ................... 9

J. Moreland Phone: (303) 497-3641; e-mail: moreland@boulder.nist.gov ............................. 28

I. Mudawar Phone: (317) 494-5705; Fax: (317) 494-0539; e-mail: mudawar@ecn.purdue.edu .............. 37

E. Novikov Phone: (619) 534-0816; Fax: (619) 534-7664; e-mail: enovikov@ucsd.edu ................... 7

E. Oblow Phone: (423) 574-6187; Fax: (423) 574-7860; e-mail: oblowem@ornl.gov ................... 33

L. Ong Phone: (301) 405-5343; e-mail: kuching@eng.umd.edu ................... ............. 21

A. Ortega Phone: (520) 621-6787; Fax: (520) 621-8191; e-mail: ortega@ccit.arizona.edu ................ 2

J. Ottino Phone: (708) 491-3558; Fax: (708) 491-3728; e-mail: ottino@chem-eng.nwu.edu .............. 31
Principal Investigators (cont'd - pg. 3)

T. Owano Phone: (415) 723-1295; Fax: (415) 723-1748; e-mail: owano@saha.stanford.edu .............. 43

L. Parker Phone: (423) 241-4959; Fax: (423) 574-7860; e-mail: parkerle@ornl.gov ..... ............... 33

D. Parks Phone: (617) 253-0033; Fax: (617) 258-8742; ....................................... 23

T. Petrosky Phone: (512) 471-7253; Fax: (512) 471-9621; e-mail: statmech@order.ph.utexas.edu ........... 44

E. Pfender Phone: (612) 625-6012; Fax: (612) 624-1398; e-mail: pfender@maroon.tc.umn.edu ............. 26

J. Plawsky Phone: (518) 276-6049; Fax: (518) 276-4030; e-mail: plawsj@rpi.edu ...................... 38

G. Pomraning Phone: (310) 825-1744; Fax: (310) 206-2302; e-mail: pomranin@seas.ucla.edu ............... 5

I. Prigogine Phone: (512) 471-7253; Fax: (512) 471-9621; e-mail: statmech@order.ph.utexas.edu ............ 44

R. Probstein Phone: (617) 253-2240; Fax: (617) 258-8559; e-mail: rfprobst@mit.edu .................... 24

A. Prosperetti Phone: (410) 516-8534; Fax: (410) 516-7254; e-mail: prosper@polaris.me.jhu.edu ............. 18

S. Putterman Phone: (310) 825-2269; Fax: (310) 206-5668; ....................................... 6

J. Ramshaw Phone: (208) 526-9240; Fax: (208) 526-6970; e-mail: jzr@inel.gov ........................ 15

N.S.V. Rao Phone: (423) 574-7517; Fax: (423) 574-7860; e-mail: raons@ornl.gov ...................... 33

W. Ray Phone: (608) 263-4732; Fax: (608) 262-0832; e-mail: ray@chewi.che.wisc.edu ............... 47

W. Reuter Phone: (208) 526-1708; Fax: (208) 526-0690; e-mail: wgr2@inel.gov ...................... 16

H. Riecke Phone: (708) 491-3345; Fax: (708) 491-2178; e-mail: h-riecke@nwu.edu . ............... 32

I. Rinard Phone: (212) 650-7135; Fax: (212) 650-6686; e-mail: rinard@che-mail.engr.ccny.cuny.edu .... .. 29

A. Rosakis Phone: (818) 395-4523; Fax: (818) 304-0175 ...................................... 10

J. Ross Phone: (415) 723-9203; Fax: (415) 723-4817; e-mail: ross@chemistry.stanford.edu ............. 43

T. Rozzell Phone: (202) 334-2908; Fax: (202) 334-2753; e-mail: trozzell@nas.edu ..................... 27

S. Russek Phone: (303) 497-5097; e-mail: russek@boulder.nist.gov ............................... 28

S. Sanders Phone: (303) 497-5096; e-mail: sanders@boulder.nist.gov ........................... ... 28

T. Scott Phone: (423) 574-5962; Fax: (423) 574-6442; e-mail: tcs@ornl.gov ....................... 33

H. Sehitoglu Phone: (217) 333-4112; Fax: (217) 244-6534; .................................... ..... 18

G. Settles Phone: (814) 863-1504; Fax: (814) 865-0118; e-mail: gss2@psu.edu ........................ 35

R. Shinnar Phone: (212) 650-6679; Fax: (212) 650-6686; e-mail: shimnar@che-mail.engr.ccny.cuny.edu ..... 29

G. Sivashinsky Phone: (212) 650-8157; Fax: (212) 650-6835; e-mail: chemw@ccnyme ..................... 29

H. Smartt Phone: (208) 526-6122; Fax: (208) 526-0690; e-mail: hbs@inel.gov ....................... 16

R. Spanos Phone: (713) 527-4909; Fax: (713) 285-5191; e-mail: spanos@rice.edu ..................... 38

R. Steeper Phone: (510) 294-2618; Fax: (510) 294-1004; e-mail: steeper@ca.sandia.gov ................ 40

G. Stephanopoulos Phone: (617) 253-4583; Fax: (617) 253-3122; e-mail: elweenw@mit.edu .................... 24

D. Stoner Phone: (208) 526-8786; Fax: (208) 526-0828; e-mail: dls2@inel.gov ....................... 15

C. Surko Phone: (619) 534-6880; Fax: (619) 534-0173; e-mail: csurko@ucsd.edu .................... 8

H. Swinney Phone: (512) 471-4619; Fax: (512) 471-1558; e-mail: swinney@chaos.ph.utexas.edu ............ 44

S. Teitel Phone: (716) 275-4039; Fax: (716) 275-8527; e-mail: stte@pas.rochester.edu ................. 38

K. Telschow Phone: (208) 526-1264; Fax: (208) 526-0690; e-mail: telsch@inel.gov ............................. 17

C. Tien Phone: (510) 642-7464; ................................... ................... 4

S. Torquato Phone: (609) 258-1309; Fax: (609) 258-1270; ....................................... 35

T. Troutt Phone: (509) 335-4375; Fax: (509) 335-4662; e-mail: troutt@mme.wsu.edu .................. 46

L. Tsimring. Phone: (619) 534-0816; Fax: (619) 534-7664; e-mail: lev@legendre.ucsd.edu ................. 8

J. Wallace Phone: (301) 405-5271; e-mail: wallace@eng.umd.edu ................... ............. 21

G. Wallis Phone: (603) 646-2789; Fax: (603) 646-3856; e-mail: graham.wallis@dartmouth.edu ........... 13

Z. Warhaft Phone: (607) 255-3898; Fax: (607) 255-1222 ....................................... 13

P. Wayner Phone: (518) 276-6199; Fax: (518) 276-4030; e-mail: wayner@rpi.edu ..................... 38

A. Westerberg Phone: (412) 268-2344; Fax: (412) 268-7139;e-mail: a.westerberg@cmu.edu ................. 10

G. Wilemski Phone: (510) 422-7919; e-mail: wilemskil@llnl.gov ................... ............... 19

F. Williams Phone: (619) 534-3168; Fax: (619) 534-4543; ....................................... 6

R. Winston Phone: (312) 702-7756; Fax: (312) 702-6317; e-mail: winston@rainbow.uchicago.edu .......... 11

E. Wolf Phone: (716) 275-4397: Fax: (716) 473-0687; ....................................... 39

I. Wygnanski Phone: (520) 621-6089; Fax: (520) 621-8191; e-mail: wygy@ccit.arizona.edu ................ 2

R. Zare Phone: (415) 723-3062; Fax: (415) 723-9262; e-mail: rnz@chemistry.stanford.edu ............. 43
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